AMENDMENT AND WAIVER AGREEMENT

Exhibit 10.32

AMENDMENT AND WAIVER AGREEMENT

     This Amendment and Waiver Agreement (this “Agreement”) is made and entered into effective as of September 20, 2007, by and among TomoTherapy Incorporated, a Wisconsin corporation (the “Company”), and the undersigned Persons and entities listed on Exhibit A hereto (the “Investors”). Capitalized terms not otherwise defined herein shall have the meanings ascribed to such terms in the Investment Agreement (as defined below).

RECITALS

     WHEREAS, the Investors and the Company have entered into that certain Amended and Restated Investment Agreement dated as of February 8, 2007 (as modified by this Agreement, the “Investment Agreement”); and

     WHEREAS, certain Rightholders desire to implement a Demand Registration of a portion of such Investors’ Registrable Securities pursuant to a Registration Statement on Form S-1 that the Company anticipates filing with the Securities and Exchange Commission in September 2007 (the “Proposed Offering”); and

     WHEREAS, in connection with the Proposed Offering, the Company and the Investors desire to allow the registration under the Securities Act of a portion of the Common Shares held by Persons other than the Investors but for which the orderly sale of such Common Shares in the Proposed Offering would likely be in the best interests of the Investors.

     NOW, THEREFORE, in consideration of the mutual representations, warranties and covenants contained herein, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

AGREEMENT

     1. Demand Registration. The Company and each Investor hereby acknowledges that the Proposed Offering constitutes a Demand Registration under Section 2.1(a) of the Investment Agreement.

     2. Amendment of Section 2.1(a). Each Investor hereby agrees that for purposes of the Proposed Offering only:

     (a) the fourth sentence of Section 2.1(a) shall be deleted and replaced with the following sentence:

     “Notwithstanding any other provision of this section, if the managing underwriter determines that marketing factors require a limitation on the number of shares to be underwritten, then the Company shall so advise the Rightholders which would otherwise be underwritten pursuant to this provision, and the number of shares that may be included in the underwriting shall be allocated

among the Rightholders and the Other Shareholders (as defined below), subject to the Participation Cap (as defined below), in proportion, as nearly as practicable, to the respective amounts of Investor Eligible Securities (as defined below) held by such Rightholders and Other Eligible Securities held by such Other Shareholders.”

     3. Waiver of Restriction on Grants of Registration Rights. The Company and each Investor hereby waives the provisions of Section 2.8 of the Investment Agreement to the extent necessary to permit the registration under the Securities Act in the Proposed Offering of;

               (a) Common Shares held by any Investor that are: (i) Registrable Securities; (ii) Common Shares acquired prior to the Company’s initial public offering, which are not Registrable Securities; and (iii) Common Shares issued or issuable upon the exercise of options or warrants that vested prior to or on August 31, 2007 (collectively, the “Investor Eligible Securities”); and

               (b) Common Shares held by any Persons other than Investors (“Other Shareholders”) that are (i) Common Shares acquired prior to the Company’s initial public offering, which are not Registrable Securities; and (ii) Common Shares issued or issuable upon the exercise of options or warrants that vested prior to or on August 31, 2007 ((i) and (ii) collectively, the “Other Eligible Securities”);

provided that the maximum number of Common Shares to be sold by the Other Shareholders in the Proposed Offering may not exceed thirty percent (30%) of the total number of Common Shares sold in the Proposed Offering (the “Participation Cap”).

     4. Waiver of Notice Requirements. The Company and each Investor hereby waives all notice and timing requirements set forth in Section 2.1 of the Investment Agreement as they relate to the Proposed Offering and acknowledges that this Agreement constitutes sufficient notice under the Investment Agreement.

     5. Effectiveness; Miscellaneous.

               (a) This Agreement shall become effective as of the first date first set forth above. Upon the earlier to occur of (i) the consummation of the Proposed Offering, or (ii) December 31, 2007, the amendments and waivers effected by this Agreement shall no longer be in effect and the Agreement shall be automatically amended to read in its entirety as it read prior to the effectiveness hereof (except that the Proposed Offering shall be considered a demand registration thereunder for purposes of the number of demand registrations required to be effected by the Company).

               (b) This Agreement and the Investment Agreement constitute the entire agreement and understanding of the parties with respect to the subject matter hereof and such agreements supersedes any and all prior agreements and understandings, oral or written, relating to the subject matter hereof.

               (c) Section headings used herein are for convenience of reference only and are not to affect the construction of, or to be taken into consideration in interpreting, this Agreement.

               (d) The laws of the State of Wisconsin shall govern the interpretation, validity and performance of the terms of this Agreement, regardless of the law that might be applied under applicable principles of conflicts of laws.

               (e) Each reference to a party hereto shall be deemed to include its successors and assigns, all of whom shall be bound by this Agreement and to whose benefit the provisions of this Waiver shall inure.

               (f) This Agreement may be executed via facsimile or by other electronic signature.

               (g) This Agreement may be executed in any number of counterparts, each of which shall be an original but all of which, when taken together, shall constitute but one instrument.

[Signature pages follow]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

				INVESTOR:
				/s/ Paul J. Reckwerdt
				Paul J. Reckwerdt
		Notices:		Paul J. Reckwerdt
				c/o TomoTherapy Incorporated
				1240 Deming Way
				Madison, WI 53717-1954
				Phone: (608) 824-2849
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Attn: Matt Hermann
				Phone: (314) 733-8112
				Fax: (314) 733-8002
				Email: [email protected]
				Attn: Jamie Wehrung
				Phone: (314) 733-8116
				Fax: (314) 733-8002
				Email: [email protected]
		With a copy to:		Joseph R. Impicciche, Esquire
				Senior Vice President, Legal Services and General Counsel
				Ascension Health
				4600 Edmundson Rd.
				St. Louis, MO 63134
				Phone: (314) 733-8286
				Fax: (314) 733-8013
				E-mail: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Stephen C. Hathaway
				c/o TomoTherapy Incorporated
				1240 Deming Way
				Madison, WI 53717-1954
				Phone: (608) 824-2838
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Stephen C. Hathaway
				c/o TomoTherapy Incorporated
				1240 Deming Way
				Madison, WI 53717-1954
				Phone: (608) 824-2838
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Stephen C. Hathaway
				c/o TomoTherapy Incorporated
				1240 Deming Way
				Madison, WI 53717-1954
				Phone: (608) 824-2838
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o Avalon Portfolio, LLC
				5786 LaJolla Blvd.
				LaJolla, CA 92037
				Attn: Jon McCloskey
				Phone: (858) 551-4429
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		ADVANTAGE CAPITAL WISCONSIN
		PARTNERS I, LIMITED PARTNERSHIP
		By: Venture Investors LLC
		Its: Sub-Manager

		Notices:		c/o Venture Investors LLC
				505 South Rosa Road, #100
				Madison, WI 53719-1262
				Attn: John Neis, Managing Director
				Phone: (608) 441-2700
				Fax: (608) 441-2727
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		BAIRD VENTURE PARTNERS I
		LIMITED PARTNERSHIP
		By: Baird Venture Partners Management Company I, L.L.C.
		Its: General Partner

		Notices:		c/o Baird Venture Partners
				227 West Monroe Street, 22nd Floor
				Chicago, IL 60606-5055
				Attn: Michael Liang
				Phone: (312) 609-5999
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		BVP I AFFILIATES FUND
		LIMITED PARTNERSHIP
		By: Baird Venture Partners Management Company I, L.L.C.
		Its: General Partner

		Notices:		c/o Baird Venture Partners
				227 West Monroe Street, 22nd Floor
				Chicago, IL 60606-5055
				Attn: Michael Liang
				Phone: (312) 609-5999
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		OPEN PRAIRIE VENTURES I, L.P.
		By: Open Prairie Ventures Management I, LLC
		Its: General Partner
		By: Open Prairie Ventures, Inc.
		Its: Manager

		Notices:		Open Prairie Ventures
				400 East Jefferson, P.O. Box 187
				Effingham, IL 62401
				Attn: Jim Schultz
				Phone: (217) 347-1010
				Fax: (217) 347-1001
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		The Endeavors Group, LLC
				Attn: Kevin Lindsey
				9100 N. Swan Rd.
				Milwaukee, WI 53224-1704
				Phone: (414) 355-3000
				Fax: (414) 355-8060
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o Godfrey & Kahn
				One East Main Street, Suite 500
				Madison, WI 53703
				Attn: Michael E. Skindrud
				Phone: (608) 284-2619
				Fax: (608) 257-0609
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		SKL Investment Group, LLC
				121 S. 17th Street
				Mattoon, IL 61938
				Attn: Steve Grissom
				Phone: (217) 235-4410
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o Schultz Investment Company
				PO Box 218
				Effingham, IL 62401
				Attn: Bob Schultz
				Phone: (217) 342-0802
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Wade Fetzer III
				c/o Goldman, Sachs & Co.
				4900 Sears Tower
				Chicago, IL 60606-6372
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Frank J. Gambino
				1007 Farwell Court
				Madison, WI 53704
				Phone: (608) 240-9639
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		David A. Hackworthy
				639 Summit Road
				Madison, WI 53704
				Phone: (608) 241-2988
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		2136 Van Hise Avenue
				Madison, WI 53705
				Phone: (608) 233-4400
				Or
				P.O. Box 392
				Madison, WI 53701-0392
				Phone: (608) 251-2351
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Terry F. and Mary W. Kelly
				1007 Hillside Avenue
				Madison, WI 53705-1116
				Phone (work): (608) 274-5789
				Phone (home): (608) 238-3734
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Thomas S. King
				3582 Bishops Way
				Middleton, WI 53562
				Phone: (608) 242-4100 ext. 30373
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Max G. and Shelley M. Lagally
				5110 Juneau Road
				Madison, WI 53705-4744
				Phone: (608) 233-0071
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement r as of the date first written above.

		Notices:		Michael G. Laskis
				c/o Foley & Lardner
				150 E. Gilman Street, PO Box 1497
				Madison, WI 53701-1497
				Phone: (608) 257-5035
				Fax: (608) 258-4258
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Kevin Lindsey
				c/o The Endeavors Group, LLC
				9100 N. Swan Road
				Milwaukee, WI 53224-1704
				Phone: (414) 355-3000
				Fax: (414) 355-8060
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o McDonough Medical Products Corp.
				1407 Barclay Boulevard
				Buffalo Grove, IL 60089
				Phone: (847) 325-9774
				Fax: (847) 541-8452
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Allison J. McDonough
				756 Mawman Avenue
				Lake Bluff, IL 60044
				Phone: (847) 615-9432
				Fax: (312) 215-5080
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o McDonough Medical Products Corp.
				1407 Barclay Boulevard
				Buffalo Grove, IL 60089
				Phone: (847) 325-9774
				Fax: (847) 541-8452
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		John J. McDonough, Jr.
				8225 Cobblestone Drive
				Austin, TX 78735
				Phone: (512) 394-0329
				Fax: (512) 418-0111
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Joseph F. McDonough
				6990 Apprentice Place
				Middleton, WI 53562
				Phone: (608) 831-2292
				Fax: (425) 645-0313
				E-mail: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Dana L. McDonough
				310 Ravine Forest Drive
				Lake Bluff, IL 60045
				Phone: (847) 735-9772
				Fax: (847) 735-9678
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Cary J. Nolan
				10028 Hobart Road
				Kirtland, OH 44094-9723
				Phone: (440) 256-3903/3904
				Fax: (440) 256-2900
				Fax (winter): (949) 376-4554
				Mobile: (216) 314-5651
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Christopher L. Rizik
				c/o Ardesta Employees’ 401(k) Savings &
				Investment Plan
				201 S. Main Street, Suite 1000
				Ann Arbor, MI 48104
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Anne E. Ross
				c/o Foley & Lardner
				150 E. Gilman Street, PO Box 1497
				Madison, WI 53701-1497
				Phone: (608) 257-5035
				Fax: (608) 258-4258
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Ronald D. Sippel
				1312 Church Street
				Evanston, IL 60201
				Phone: (312) 559-8891
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Dennis Skogen
				3154 Wacheeta Trail
				Madison, WI 53711-5952
				Phone: (608) 222-8600
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o Richard D. Snyder
				201 S. Main Street, Suite 1000
				Ann Arbor, MI 48104

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Marc Vaintrub
				843 West Webster Avenue
				Chicago, IL 60614
				Phone: (773) 525-1791
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		David G. Walsh
				c/o Foley & Lardner
				150 E. Gilman Street
				Madison, WI 53703-2808
				Phone: (608) 257-5035
				Fax: (608) 258-4258
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o Allan A. Weissburg
				11502 Hemingway Drive
				Reston, VA 20194-1252
				Phone: (703) 467-9855
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o David Weissburg
				4213 Winnequah Road
				Monona, WI 53716-1057
				Phone: (608) 221-0023
				Fax: (608) 221-9055
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		David Weissburg
				4213 Winnequah Road
				Monona, WI 53716-1057
				Phone: (608) 221-0023
				Fax: (608) 221-9055
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		c/o David Weissburg
				4213 Winnequah Road
				Monona, WI 53716-1057
				Phone: (608) 221-0023
				Fax: (608) 221-9055
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		121 East Wilson Street
				Madison, WI 53702
				Attn: Chris Prestigiacomo, Portfolio Manager
				Phone: (608) 266-6723
				Fax: (608) 266-2436
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		VENTURE INVESTORS EARLY STAGE FUND
		II LIMITED PARTNERSHIP
		By: Venture Investors Founders, L.P.
		Its: General Partner
		By: Venture Investors LLC
		Its: General Partner

		Notices:		c/o Venture Investors LLC
				505 South Rosa Road, #100
				Madison, WI 53719-1262
				Attn: John Neis, Managing Director
				Phone: (608) 441-2700
				Fax: (608) 441-2727
				Email: [email protected]

     [Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		INVESTOR:
		VENTURE INVESTORS EARLY STAGE FUND III LIMITED PARTNERSHIP
		By: Venture Investors LLC
		Its: General Partner

		Notices:
				505 South Rosa Road, #100
				Madison, WI 53719-1262
				Attn: John Neis, Managing Director
				Phone: (608) 441-2700
				Fax: (608) 441-2727
				Email: [email protected]

[Signature to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		614 Walnut Street (53705)
				P.O. Box 7365
				Madison, WI 53707-7365
				Attn: Carrie J. Thome, Associate Director of
				Investments
				Phone: (608) 263-2500
				Fax: (608) 263-1064
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		James Hanson
				3440 Highpoint Road
				Madison, WI 53719
				Phone (Mobile): (608) 358-0500
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		P. Schaefer and Amy J. Price
				c/o Pharmasset
				303 College Road East
				Princeton, NJ 08540
				Phone: (404) 325-5183
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Attn: Nathan L. Stacy
				Mayo Medical Ventures
				200 First Street, S.W.
				Rochester, MN 55905
				Phone: (507) 538-1652
				Fax: (507) 284-5410
				E-mail: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		Attn: Dr. Jose Luis Pino-y-Torres
				22 Shady Lane
				Sparta, NJ 07871
				Phone: (973) 726-8718
				Mobile: (407) 367-9731
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment and Waiver Agreement as of the date first written above.

		Notices:		John J. Barni
				900 W. Hill Drive
				Gates Mills, OH 44040-9684
				Home: (440) 423-0747
				Mobile: (440) 655-3889
				Email: [email protected]

[Signature Page to Amendment and Waiver Agreement]

EXHIBIT A

Investors

Reckwerdt, Paul J.
Barni, John
Stephen C. Hathaway and Elaine M. Hathaway, as
     Trustees of the Hathaway Revocable Trust under
     agreement dated February 10, 2005
Stephen C. Hathaway Grantor Retained Annuity Trust
Elaine M. Hathaway Grantor Retained Annuity Trust
Avalon Technology, LLC
Wisconsin Alumni Research Foundation
Venture Investors Early Stage Fund III L.P.
Venture Investors Early Stage Fund II L.P.
Advantage Capital Wisconsin Partners I, L.P.
Open Prairie Ventures I, L.P.
Mayo Foundation for Medical Education and Research
Endeavors Group, LLC, The
AKRA Investments, LLC
Ardesta Employees’ 401(k) Savings & Retirement
     Plan, f/b/o Christopher Rizik
Ascension Health
780 TomoTherapy Partners
Baird Venture Partners I L.P.
BVP I Affiliates Fund L.P.
Fetzer III, Wade
Gambino, Frank J.
Grey Ghost LLC
Hackworthy, David A.
Hackworthy Family Trust
Hanson, James
Kelly, Terry F. and Mary W.
King, Thomas S.
Laskis, Michael G.
Lindsey, Kevin
McDonough, John J.
McDonough, Allison J.
McDonough, Edwin J.
McDonough, John J. Jr.
McDonough, Joseph F.
McDonough, Dana L.
Nolan, Cary
Price, P. Schaefer and Amy J.
Ross, Anne E.
Ronald D. Sippel Revocable Trust

SKL Investment Group, LLC
Skogen, Dennis
Richard D. Snyder Revocable Trust
Sunshine Summit, LLC
Vaintrub, Marc
Walsh, David G.
Weissburg, Allan A. Revocable Trust
Weissburg, David and Leslie, as joint tenants with
     right of survivorship
Weissburg, David
Weissburg, Leslie
State of Wisconsin Investment Board