“ Registration Expenses ” shall mean the expenses so described in Section 8.

“ Restricted Stock ” shall mean (i) the Conversion Shares, excluding Conversion Shares which have been (a) registered under the Securities Act pursuant to an effective registration statement filed thereunder and disposed of in accordance with the registration statement covering them or (b) publicly sold pursuant to Rule 144 under the Securities Act, and (ii) any shares of Common Stock issued or distributed in respect of the securities described in clause (i).

“ Securities Act ” shall mean the Securities Act of 1933 or any similar federal statute, and the rules and regulations of the Commission thereunder, all as the same shall be in effect at the time.

“ Selling Expenses ” shall mean the expenses so described in Section 8.

“ Series F Preferred Stock ” shall mean the Series F Participating Convertible Preferred Stock, par value $.001 per share, of the Company, constituted as of July 31, 2003.

“ Series G Preferred Stock ” shall mean the Series G Participating Convertible Preferred Stock of the Company, constituted as of July 31, 2003.

“ Series I Preferred Stock ” shall mean the Series I Participating Convertible Preferred Stock of the Company, constituted as of January 5, 2004.

“ Series J Preferred Stock ” shall mean the Series J Participating Convertible Preferred Stock of the Company, constituted as of March 30, 2004.

“ Series K Preferred Stock ” shall mean the Series K Participating Convertible Preferred Stock of the Company constituted as of August 12, 2004.

“ Series L Preferred Stock ” shall mean the Series L Participating Convertible Preferred Stock of the Company, issued as of September 15, 2004.

“ Series M Preferred Stock ” shall mean the Series M Participating Convertible Preferred Stock of the Company, issued as of the date of this Agreement.

2.                                        Restrictive Legend .  Each certificate representing Preferred Stock, Conversion Shares or Restricted Stock shall, except as otherwise provided in this Section 2 or in Section 3, be stamped or otherwise imprinted with a legend substantially in the following form:

“The securities represented by this certificate have not been registered under the Securities Act of 1933 or applicable state securities laws.  These securities have been acquired for investment and not with a view to distribution or resale, and may not be sold mortgaged, pledged, hypothecated or otherwise transferred without an effective registration

statement for such securities under the Securities Act of 1933 and applicable state securities laws, or the availability of an exemption from the registration provisions of the Securities Act of 1933 and applicable state securities laws.”

A certificate shall not bear such legend if in the opinion of counsel reasonably satisfactory to the Company the securities being sold thereby may be publicly sold without registration under the Securities Act.

3.                                        Notice of Proposed Transfer .  Prior to any proposed transfer of any Preferred Stock, Conversion Shares or Restricted Stock (other than under the circumstances described in Sections 4, 5 or 6), the holder thereof shall give written notice to the Company of its intention to effect such transfer.  Each such notice shall describe the manner of the proposed transfer and, if requested by the Company, shall be accompanied by an opinion of counsel reasonably satisfactory to the Company to the effect that the proposed transfer may be effected without registration under the Securities Act, whereupon the holder of such stock shall be entitled to transfer such stock in accordance with the terms of its notice; provided , however , that no such opinion of counsel shall be required for a transfer to one or more partners of the transferor (in the case of a transferor that is a partnership), to one or more members of the transferor (in the case of a transferor that is a limited liability company) or to an affiliated corporation (in the case of a transferor that is a corporation);  provided , further , however , that any transferee other than a partner, member or affiliate of the transferor shall execute and deliver to the Company a representation letter in form reasonably satisfactory to the Company’s counsel to the effect that the transferee is acquiring Restricted Stock for its own account, for investment purposes and without any view to distribution thereof.  Each certificate for Preferred Stock or Conversion Shares transferred as above provided shall bear the legend set forth in Section 2, except that such certificate shall not bear such legend if (i) such transfer is in accordance with the provisions of Rule 144 (or any other rule permitting public sale without registration under the Securities Act) or (ii) the opinion of counsel referred to above is to the further effect that the transferee and any subsequent transferee (other than an affiliate of the Company) would be entitled to transfer such securities in a public sale without registration under the Securities Act.  The restrictions provided for in this Section 3 shall not apply to securities which are not required to bear the legend prescribed by Section 2 in accordance with the provisions of that Section.

4.                                        Required Registration .

(a)                                   Subject to Section 13(f) of this Agreement, at any time after the earlier of (i) July 31, 2006 and (ii) the date that is six (6) months after the first public offering after the date hereof of securities by the Company, holders of Restricted Stock constituting more than 50% of the total number of shares of Restricted Stock then outstanding may request the Company to register under the Securities Act all or any portion of the shares of Restricted Stock held by such requesting holder or holders for sale in the manner specified in such notice.  For purposes of this Section 4 and Sections 5, 6, 13(a) and 13(d), the term “Restricted Stock” shall be deemed to include the number of shares of Restricted Stock which would be issuable to a holder of Preferred Stock upon conversion of all shares of

Preferred Stock held by such holder at such time; provided , however , that the only securities which the Company shall be required to register pursuant hereto shall be shares of Common Stock; provided , further , however , that, in any underwritten public offering contemplated by this Section 4 or Sections 5 and 6, the holders of Preferred Stock shall be entitled to sell such Preferred Stock to the underwriters for conversion and sale of the shares of Common Stock issued upon conversion thereof and holders of a majority of the Preferred Stock being so registered shall have the right to approve the managing underwriter(s) selected by the Company in connection with such underwritten public offering.  Notwithstanding anything to the contrary contained herein, the Company shall not be obligated to effect a registration (i) during the 180 day period commencing with the effective date of a registration statement filed by the Company covering the first firm commitment underwritten public offering after the date hereof or (ii) if the Company delivers notice to the holders of the Restricted Stock within thirty (30) days of any registration request of the Company’s intent to file a registration statement for an underwritten public offering within ninety (90) days.

(b)                                  Following receipt of any notice under this Section 4, the Company shall immediately notify all holders of Restricted Stock and Preferred Stock from whom notice has not been received and such holders shall then be entitled within 30 days thereafter to request the Company to include in the requested registration all or any portion of their shares of Restricted Stock.  The Company shall use its best efforts to register under the Securities Act, for public sale in accordance with the method of disposition described in paragraph (a) above, the number of shares of Restricted Stock specified in such notice (and in all notices received by the Company from other holders within 30 days after the giving of such notice by the Company).  The Company shall be obligated to register Restricted Stock pursuant to this Section 4 on three occasions only; provided , however , that such obligation shall be deemed satisfied only when a registration statement covering all shares of Restricted Stock specified in notices received as aforesaid for sale in accordance with the method of disposition specified by the requesting holders shall have become effective and, if such method of disposition is a firm commitment underwritten public offering, all such shares shall have been sold pursuant thereto.

(c)                                   The Company (or at the option of the Company, the holders of Common Stock) shall be entitled to include in any registration statement referred to in this Section 4, for sale in accordance with the method of disposition specified by the requesting holders, shares of Common Stock to be sold by the Company or such other holders for its own account, except as and to the extent that, in the opinion of the managing underwriter (if such method of disposition shall be an underwritten public offering), such inclusion would adversely affect the marketing of the Restricted Stock to be sold.  Subject to Section 4(a) and except for registration statements on Form S-4, S-8 or any successor thereto, the Company will not file with the Commission any other registration statement with respect to its Common Stock, whether for its own account or that of other stockholders, from the date of receipt of a notice from requesting holders pursuant to this Section 4 until the completion of the period of distribution of the registration contemplated thereby.

(d)                                  If, in the opinion of the managing underwriter, the inclusion of all of the Restricted Stock requested to be registered under this Section would adversely affect the

marketing of such shares, the Company shall only include the number of shares that, in the reasonable opinion of such underwriter, can be sold without having an adverse effect on the marketing of such shares, to be allocated to each stockholder of the Company on a pro rata basis based on the total number of shares held by such holder and requested to be included in the registration; provided , however , that the number of shares of Restricted Stock to be included in such underwriting and registration shall not be reduced unless all other securities of the Company are first excluded from the underwriting and registration.

5.                                        Incidental Registration .  Subject to Section 13(f) of this Agreement, if the Company at any time (other than pursuant to Section 4 or Section 6) proposes to register any of its securities under the Securities Act for sale to the public, whether for its own account or for the account of other security holders or both (except with respect to registration statements on Forms S-4, S-8 or another form not available for registering the Restricted Stock for sale to the public), each such time it will give written notice to all holders of outstanding Restricted Stock of its intention so to do.  Upon the written request of any such holder, received by the Company within 30 days after the giving of any such notice by the Company, to register any of its Restricted Stock, the Company will use its best efforts to cause the Restricted Stock as to which registration shall have been so requested to be included in the securities to be covered by the registration statement proposed to be filed by the Company, all to the extent requisite to permit the sale or other disposition by the holder (in accordance with its written request) of such Restricted Stock so registered.  In the event that any registration pursuant to this Section 5 shall be, in whole or in part, an underwritten public offering of Common Stock, if the managing underwriter determines in good faith that marketing factors require a limitation of the number of shares to be underwritten, the number of shares that may be included in the underwriting shall be allocated, first, to the Company; second, to the holders of Restricted Stock invoking the rights under this Section 5 on a pro rata basis based on the total number of shares of Restricted Stock held by such holders; and third, to any stockholder of the Company (other than such holders) on a pro rata basis.  No such reduction shall reduce the amount of securities of the selling holders included in the registration below thirty percent (30%) of the total amount of securities included in such registration.  In no event will shares of any other selling stockholder be included in such registration that would reduce the number of shares which may be included by holders of Restricted Stock without the written consent of the holders of not less than sixty-six and two-thirds percent (66 2/3%) of the Restricted Stock proposed to be sold in the offering.  If any such holder disapproves of the terms of any such underwriting, such holder may elect to withdraw therefrom by written notice to the Company and the underwriter, delivered at least ten (10) business days prior to the effective date of the registration statement.  Any shares of Restricted Stock excluded or withdrawn from such underwriting shall be excluded and withdrawn from the registration.  For any holder which is a partnership or corporation, the partners, retired partners and stockholders of such holder, or the estates and family members of any such partners and retired partners and any trusts for the benefit of any of the foregoing person shall be deemed to be a single holder, and any pro rata reduction with respect to such holder shall be based upon the aggregate amount of shares carrying registration rights owned by all entities and individuals included in such holder, as defined in this sentence.  Notwithstanding the foregoing provisions, the Company may withdraw any registration statement referred to in this Section 5 without thereby incurring any liability to the holders of

Restricted Stock.

6.                                        Registration on Form S-3 .  Subject to Section 13(f) of this Agreement, if at any time (i) a holder or holders of Restricted Stock then outstanding request that the Company file a registration statement on Form S-3 or any successor thereto for a public offering of all or any portion of the shares of Restricted Stock held by such requesting holder or holders, and (ii) the Company is a registrant entitled to use Form S-3 or any successor thereto to register such shares, then the Company shall use its best efforts to register under the Securities Act on Form S-3 or any successor thereto for public sale in accordance with the method of disposition specified in such notice, the number of shares of Restricted Stock specified in such notice.  Whenever the Company is required by this Section 6 to use its best efforts to effect the registration of Restricted Stock, each of the procedures and requirements of Section 4 (including but not limited to the requirement that the Company notify all holders of Restricted Stock from whom notice has not been received and provide them with the opportunity to participate in the offering) shall apply to such registration; provided , however , that there shall be no limitation on the number of registrations on Form S-3 which may be requested and obtained under this Section 6 and registrations effected pursuant to this Section 6 shall not be counted as demands for registration or registrations effected pursuant to Sections 4 or 5, respectively.

(b)                                  Notwithstanding anything to the contrary set forth in this Agreement, the Company’s obligation under this Agreement to register Restricted Stock under the Securities Act on registration statements (“ Registration Statements ”) may, upon the reasonable determination of the Board of Directors made not more than twice in the aggregate (and not more than once with respect to a Registration Statement on Form S-1 and not more than once with respect to a Registration Statement on Form S-3 and including any delay pursuant to the last sentence of Section 4(a)) during any 12-month period, be suspended in the event and during such period as unforeseen circumstances (including without limitation (i) an underwritten primary offering by the Company (which includes no secondary offering) if the Company is advised in writing by its underwriters that the registration of the Restricted Stock would have a material adverse effect on the Company’s offering, or (ii) pending negotiations relating to, or consummation of, a transaction or the occurrence of an event which would require additional disclosure of material information by the Company in Registration Statements or such other filings, as to which the Company has a bona fide business purpose for preserving confidentiality or which renders the Company unable to comply with the Commission’s requirements) exist (such unforeseen circumstances being hereinafter referred to as a “ Suspension Event ”) which would make it impractical or unadvisable for the Company to file the Registration Statements or such other filings or to cause such to become effective.  Such suspension shall continue only for so long as such event is continuing but in no event for a period longer than (i) one hundred and twenty (120) days, in the case of a Registration Statement on Form S-1 (or any successor thereto) or (ii) ninety (90) days, in the case of a Registration Statement on Form S-3 (or any successor thereto).  The Company shall notify the Purchasers of the existence and nature of any Suspension Event.

7.                                        Registration Procedures .  If and whenever the Company is required by the

provisions of Sections 4, 5 or 6 to use its best efforts to effect the registration of any shares of Restricted Stock under the Securities Act, the Company will, as expeditiously as possible:

(a)                                   prepare and file with the Commission a registration statement (which, in the case of an underwritten public offering pursuant to Section 4, shall be on Form S-1 or other form of general applicability satisfactory to the managing underwriter selected as therein provided) with respect to such securities and use its best efforts to cause such registration statement to become and remain effective for the period of the distribution contemplated thereby (determined as hereinafter provided);

(b)                                  prepare and file with the Commission such amendments and supplements to such registration statement and the prospectus used in connection therewith as may be necessary to keep such registration statement effective for the period specified in paragraph (a) above and comply with the provisions of the Securities Act with respect to the disposition of all Restricted Stock covered by such registration statement in accordance with the sellers’ intended method of disposition set forth in such registration statement for such period;

(c)                                   furnish to each seller of Restricted Stock and to each underwriter such number of copies of the registration statement and each such amendment and supplement thereto (in each case including all exhibits) and the prospectus included therein (including each preliminary prospectus) as such persons reasonably may request in order to facilitate the public sale or other disposition of the Restricted Stock covered by such registration statement;

(d)                                  use its best efforts to register or qualify the Restricted Stock covered by such registration statement under the securities or “blue sky” laws of such jurisdictions as the sellers of Restricted Stock or, in the case of an underwritten public offering, the managing underwriter reasonably shall request; provided , however , that the Company shall not for any such purpose be required to qualify generally to transact business as a foreign corporation in any jurisdiction where it is not so qualified or to consent to general service of process in any such jurisdiction;

(e)                                   use its best efforts to list the Restricted Stock covered by such registration statement with any securities exchange on which the Common Stock of the Company is then listed;

(f)                                     immediately notify each seller of Restricted Stock and each underwriter under such registration statement, at any time when a prospectus relating thereto is required to be delivered under the Securities Act, of the happening of any event of which the Company has knowledge as a result of which the prospectus contained in such registration statement, as then in effect, includes an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances then existing, and promptly prepare and furnish to such seller a reasonable number of copies of a prospectus supplemented or amended so that, as thereafter delivered to the purchasers of such Restricted Stock, such

prospectus shall not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstance