CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Net income (loss)	$ 3,119	$ (4,594)
Adjustments required to reconcile net income (loss) to net cash provided by (used for) operating activities:
Depreciation and amortization	842	1,046
Bad debt expense	8	15
Stock-based compensation	2,679	2,332
Write-down of inventory	252	156
Deferred tax provision	90	96
Changes in assets and liabilities:
Accounts receivable	2,032	847
Inventories	(1,982)	(1,601)
Prepaid expenses and other assets	(65)	220
Accounts payable	(300)	(1,360)
Accrued expenses and other long-term liabilities	(2,024)	(5,443)
Deferred revenue	(333)	(270)
Net cash provided by (used for) operating activities	4,318	(8,556)
Investing activities:
Purchases of short-term marketable securities	(11,500)	(5,001)
Proceeds from the sale and maturity of short-term marketable securities	5,500	4,500
Expenditures for property and equipment	(470)	(472)
Net cash used for investing activities	(6,470)	(973)
Financing activities:
Proceeds from the exercise of stock options	1,228	7,629
Payments in lieu of issuance of common stock for minimum payroll taxes	(238)
Net cash provided by financing activities	990	7,629
Effect of exchange rate changes on cash	(839)	220
Net decrease in cash and cash equivalents	(2,001)	(1,680)
Cash and cash equivalents at beginning of period	5,990	5,831
Cash and cash equivalents at end of period	3,989	4,151
Supplemental disclosures:
Fixed asset additions included in accounts payable	$ 92	$ 44