Consolidated Statements of Cash flows (Unaudited) (USD $)	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating Activities:
Net loss	$ (2,275,100)	$ (1,851,994)
Adjustments to reconcile net loss to net cash (used) provided by operating activities:
Loss on impairment	1,350,504
Depreciation and amortization	4,117,580	3,128,328
Loss on write down / disposal of property and equipment, net	757,038	34,442
Provision for doubtful accounts	14,580	2,764
Provision / write-off of excess and obsolete inventory	328,870	806,350
Provision for warranty	79,886	321,137
Stock-based compensation expense	1,839,924	1,926,220
Litigation judgment accrual	3,301,243
Deferred income taxes	(1,744,706)	(1,427,397)
Provision for unrecognized tax benefits	(1,989)	(65,159)
Change in assets and liabilities:
Accounts receivable	3,546,984	4,383,916
Inventory	1,044,680	(4,797,031)
Prepaids and other assets	(1,592,862)	(2,705,926)
Accounts payable and accrued liabilities	(599,996)	(2,159,154)
Deferred revenue	(915,816)	119,355
Customer deposits	(95,728)	(105,793)
Net cash provided (used) by operating activities	9,155,092	(2,389,942)
Cash Flows from Investing Activities:
Purchases of investments	(10,775,112)
Purchases of property and equipment	(659,872)	(3,193,856)
Purchases of intangible assets	(213,276)	(180,053)
Net cash used by investing activities	(11,648,260)	(3,373,909)
Cash Flows from Financing Activities:
Repurchase of common stock	(12,499,816)
Proceeds from stock options exercised	3,923	961,037
Net cash (used) provided by financing activities	(12,495,893)	961,037
Effect of exchange rate change on cash and cash equivalents	24,225	(102,981)
Net decrease in cash and cash equivalents	(14,989,061)	(4,802,814)
Cash and cash equivalents, beginning of period	42,684,241	45,505,049
Cash and cash equivalents, end of period	27,719,405	40,599,254
Supplemental Disclosure:
Cash paid for income taxes	36,000	528,532
Non-Cash Transactions:
Property and equipment purchases in accounts payable	$ 507,260	$ 39,134