August 24, 2007

VIA EDGAR AND U.S. MAIL

Ms. Linda van Doorn

Senior Assistant Chief Accountant

U.S. Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Form 10-K for the Fiscal Year Ended December 31, 2006

File No. 001-31458

Dear Ms. van Doorn:

We have received the letter dated July 19, 2007 (the “Letter”), from the Staff of the Division of Corporation Finance (the “Staff”) of the Securities and Exchange Commission (the “SEC” or “Commission”) with respect to its review of the Company’s Form 10-K for the fiscal year ended December 31, 2006 (the “filing”) filed on February 26, 2007.

We note that the Letter requested that the Company file a response to the comments contained therein within 10 business days. The Letter was addressed to our Chief Executive Officer, Kenneth M. Riis, and sent through the Company’s internal mail to the Company’s San Diego offices. Mr. Riis has been working at the Company’s New York offices since mid-July 2007, and the Letter was inadvertently not brought to his attention while he was working in New York. Consequently, Mr. Riis did not become aware of the Letter until he returned to the Company’s San Diego offices today, August 24, 2007. As soon as he became aware of the Letter, the Company contacted the Staff and explained the circumstances behind the Company’s delay in responding to the Staff’s comments. The Staff agreed to extend the Company’s deadline for filing a response to the comments set forth in the Letter until September 7, 2007.

The Company will file a complete set of thorough responses to the Staff’s comments by September 7, 2007. The Company looks forward to working with the Staff on these comments and appreciates the extension provided by the Staff.

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