Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balance at Dec. 28, 2008	$ 21,862	$ 30	$ 169,846		$ (148,014)
Balance (in shares) at Dec. 28, 2008		29,909
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under stock plans and employee stock purchase plans, shares		827
Common stock issued under stock plans and employee stock purchase plans, value	167	1	166
Private Stock Offering, net of issuance costs and warrants, shares		4,306
Private Stock Offering, net of issuance costs and warrants, value	3,435	4	3,431
Issuance of common stock warrants, value	2,035		2,035
Change in unrealized gain on available-for-sale securities	1,130			1,130
Stock-based compensation	2,384		2,384
Net income (loss)	(9,754)				(9,754)
Balance at Jan. 03, 2010	21,259	35	177,862	1,130	(157,768)
Balance (in shares) at Jan. 03, 2010		35,042
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under stock plans and employee stock purchase plans, shares		1,471
Common stock issued under stock plans and employee stock purchase plans, value	3,229	2	3,227
Private Stock Offering, net of issuance costs and warrants, value	18		18
Issuance of common stock warrants. shares		1,293
Issuance of common stock warrants, value	2,780	1	2,779
Change in unrealized gain on available-for-sale securities	(514)			(514)
Stock-based compensation	2,418		2,418
Net income (loss)	123				123
Balance at Jan. 02, 2011	29,313	38	186,304	616	(157,645)
Balance (in shares) at Jan. 02, 2011		37,806
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under stock plans and employee stock purchase plans, shares		830
Common stock issued under stock plans and employee stock purchase plans, value	2,046	1	2,045
Change in unrealized gain on available-for-sale securities	(503)			(503)
Stock-based compensation	1,676		1,676
Net income (loss)	(7,594)				(7,594)
Balance at Jan. 01, 2012	$ 24,938	$ 39	$ 190,025	$ 113	$ (165,239)
Balance (in shares) at Jan. 01, 2012		38,636