Income Taxes (Tables)

12 Months Ended

Mar. 31, 2014

A reconciliation of income tax (benefit) expense to the federal statutory rate follows (in thousands):

	Year Ended March 31,

	2014			2013			2012
Federal income tax at the statutory rate	$	(5,452	)	$	(7,436	)	$	(6,317	)
State taxes, net of federal effect		(93	)		(661	)		(727	)
Foreign taxes		134			675			313
R&D tax credit		37			(1,157	)		(455	)
Impact of state rate change		492			838			(693	)
Warrant liability		(3	)		(299	)		(5,301	)
Expiring NOL		1,543			—			9,765
Valuation allowance		3,614			(1,877	)		3,423
Excess tax benefit—stock compensation		—			10,383			—
Other		(52	)		228			178


Income tax expense (benefit)	$	220		$	694		$	186

The Company's deferred tax assets and liabilities consisted of the following at March 31, 2014 and 2013 (in thousands):

	2014			2013

Deferred tax assets:
Inventories	$	2,152		$	1,754
Warranty reserve		1,051			866
Deferred revenue		731			532
Net operating loss ("NOL") carryforwards		214,071			211,724
Tax credit carryforwards		18,369			18,295
Depreciation, amortization and impairment loss		3,631			3,997
Other		5,280			5,498


Deferred tax assets		245,285			242,666
Valuation allowance for deferred tax assets		(236,169	)		(232,555	)


Deferred tax assets, net of valuation allowance		9,116			10,111
Deferred tax liabilities:
Federal benefit of state taxes		(9,116	)		(10,111	)


Net deferred tax assets	$	—		$	—

The Company's NOL and tax credit carryforwards for federal and state income tax purposes at March 31, 2014 were as follows (in thousands):

	Amount		Expiration Period

Federal NOL	$	606,193	2018 - 2034
State NOL	$	226,861	2014 - 2034
Federal tax credit carryforwards	$	9,487	2018 - 2034
State tax credit carryforwards	$	8,882	Indefinite

A reconciliation of the beginning and ending amount of total gross unrecognized tax benefits is as follows (in thousands):


Balance at March 31, 2011	$	1,973
Gross increase related to prior year tax positions		—
Gross increase related to current year tax positions		175
Lapse of statute of limitations		—


Balance at March 31, 2012	$	2,148
Gross decrease related to prior year tax positions		(100	)
Gross increase related to prior year tax positions		222
Gross increase related to current year tax positions		148
Lapse of statute of limitations		—


Balance at March 31, 2013	$	2,418
Gross decrease related to prior year tax positions		(93	)
Gross increase related to prior year tax positions		1
Gross increase related to current year tax positions		115
Lapse of statute of limitations		—


Balance at March 31, 2014	$	2,441