D. DETAIL OF SELECTED BALANCE SHEET ACCOUNTS

Allowance for Doubtful Accounts

Activity in our allowance for doubtful accounts receivable consisted of the following (in thousands):


	Three Months Ended				Nine Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Balance at beginning of period	$	912	$	1,043	$	1,399	$	391
Increase (decrease) to bad debt expense		68		(127)		(310)		509
Deductions for uncollectible accounts written off, net of recoveries		(54)		175		(151)		175
Increase (decrease) due to foreign currency translation		(2)		5		(14)		21
Balance at end of period	$	924	$	1,096	$	924	$	1,096

Warranty Accrual

Activity in our product warranty accrual consisted of the following (in thousands):


	Three Months Ended				Nine Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Balance at beginning of period	$	5,242	$	4,783	$	5,714	$	4,603
Increase to warranty expense		430		752		1,965		2,084
Deduction for warranty charges		(874)		(1,068)		(2,798)		(2,254)
Increase (decrease) due to foreign currency translations		(7)		(40)		(90)		(6)
Balance at end of period	$	4,791	$	4,427	$	4,791	$	4,427

Inventories

The components of inventories are summarized below (in thousands):


	June 30,		September 30,
	2013		2012
Raw materials, parts and subassemblies	$	32,694	$	33,632
Work-in-progress		4,217		6,422
Provision for excess and obsolete inventory		(6,177)		(7,137)
Total inventories	$	30,734	$	32,917

Cost and Estimated Earnings on Uncompleted Contracts

The components of costs and estimated earnings and related amounts billed on uncompleted contracts are summarized below (in thousands):


	June 30,		September 30,
	2013		2012
Costs incurred on uncompleted contracts	$	605,097	$	635,714
Estimated earnings		147,503		168,480
		752,600		804,194
Less: Billings to date		745,981		754,604
Net underbilled position	$	6,619	$	49,590

Included in the accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts	$	73,806	$	86,734
Billings in excess of costs and estimated earnings on uncompleted contracts		(67,187)		(37,144)
Net underbilled position	$	6,619	$	49,590