Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating activities
Net income (loss)	$ (318)	$ 4
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	1,876	1,543
Stock-based compensation expense	657	611
Deferred income tax benefit	(567)	(1,374)
Change in allowance for notes and accounts receivable	49	64
Other	37	34
Changes in operating assets and liabilities:
Accounts receivable	4,014	2,546
Inventories	(3,337)	(7,715)
Prepaid expenses and other	(1,373)	(6,454)
Deferred revenue	2,621	991
Accounts payable	(2,095)	1,474
Accrued expenses	360	(357)
Net cash provided by (used in) operating activities	1,924	(8,633)
Investing activities
Purchase of property and equipment	(2,003)	(1,957)
Purchase of property and equipment held under operating leases	(3)	(1,630)
Purchase of short-term investments	(3)	(7)
Additions to patents and licenses	(125)	(110)
Proceeds from sales of property, plant and equipment	1	1
Long-term assets		(330)
Net cash used in investing activities	(2,133)	(4,033)
Financing activities
Payment of long-term debt	(664)	(271)
Proceeds from long-term debt	4,583	2,689
Proceeds from repayment of shareholder notes	13
Excess tax benefits from stock-based compensation	271
Deferred financing costs	(113)	(61)
Proceeds from issuance of common stock	118	269
Net cash provided by financing activities	4,208	2,626
Net increase (decrease) in cash and cash equivalents	3,999	(10,040)
Cash and cash equivalents at beginning of period	11,560	23,364
Cash and cash equivalents at end of period	15,559	13,324
Supplemental cash flow information:
Cash paid for interest	201	126
Cash paid for income taxes	63	28
Supplemental disclosure of non-cash investing and financing activities:
Shares issued from treasury for shareholder note receivable	64	121
Shares surrendered into treasury from stock option exercise		$ 51