Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Cash flows from operating activities:
Net loss	$ (9,508)	$ (1,119)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,129	882
Stock-based compensation	377	405
Deferred income taxes	0	105
Other non-cash items	(10)	(111)
Changes in assets and liabilities:
Accounts receivable	3,010	5,585
Advance billings	865	(752)
Inventories	(1,498)	(1,433)
Prepaid expenses and other current assets	1,062	2,105
Other assets	45	17
Accounts payable	3,521	1,497
Accrued liabilities	(1,173)	(933)
Deferred revenue	664	(2,710)
Income taxes payable, non-current and other liabilities	(17)	(88)
Net cash provided by (used in) operating activities	(3,263)	4,954
Cash flows from investing activities:
Purchases of property and equipment	(82)	(421)
Net cash provided by (used in) investing activities	(82)	(421)
Cash flows from financing activities:
Proceeds from stock plans, net	5	127
Net cash provided by financing activities	5	127
Effect of exchange rate changes on cash and cash equivalents	(203)	(175)
Net increase (decrease) in cash and cash equivalents	(3,543)	4,485
Cash and cash equivalents, beginning of period	14,354
Cash and cash equivalents, end of period	$ 10,811	$ 35,558