Exhibit 12.1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

	Six-months ended June 30, 2005			For the Year Ended December 31,
				2004			2003			2002			2001			2000
Earnings (loss)-
Loss before income taxes	$	(49,580	)	$	(93,271	)	$	(29,789	)	$	(34,017	)	$	(10,090	)	$	(5,847	)
Add fixed Charges:
Interest expense on indebtedness	$	3,254		$	4,480		$	990		$	1,936		$	692		$	843
Estimated interest on rental expense		951			1,611			300			329			341			305
Amortization of deferred closing costs related to convertible notes		408			521			156			294			—			—
Amortization of discount on convertible notes								271			511			—			—
Total Adjusted Loss	$	(44,967	)	$	(86,659	)	$	(28,072	)	$	(30,947	)	$	(9,057	)	$	(4,699	)
Fixed Charges -
Interest expense on indebtedness	$	3,254		$	4,480		$	990		$	1,936		$	692		$	843
Estimated interest on rental expense		951			1,611			300			329			341			305
Amortization of deferred closing costs related to convertible notes		408			521			156			294			—			—
Amortization of discount on convertible notes								271			511			—			—
Total Fixed Charges	$	4,613		$	6,612		$	1,717		$	3,070		$	1,033		$	1,148
Coverage deficiency	$	(49,580	)	$	(93,271	)	$	(29,789	)	$	(34,017	)	$	(10,090	)	$	(5,847	)