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
	December 31,
	2012		2011
Balance at beginning of period	$	1,399	$	391
Increase (decrease) to bad debt expense		(293)		185
Deductions for uncollectible accounts written off, net of recoveries		(57)		--
Increase due to foreign currency translation		1		12
Balance at end of period	$	1,050	$	588

Warranty Accrual

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


	Three Months Ended
	December 31,
	2012		2011
Balance at beginning of period	$	5,714	$	4,603
Increase to warranty expense		638		469
Deduction for warranty charges		(596)		(649)
Decrease due to foreign currency translations		(2)		(27)
Balance at end of period	$	5,754	$	4,396

Inventories

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


	December 31,		September 30,
	2012		2012
Raw materials, parts and subassemblies	$	32,878	$	33,632
Work-in-progress		5,365		6,422
Provision for excess and obsolete inventory		(6,952)		(7,137)
Total inventories	$	31,291	$	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):


	December 31,		September 30,
	2012		2012
Costs incurred on uncompleted contracts	$	597,821	$	635,714
Estimated earnings		145,189		168,480
		743,010		804,194
Less: Billings to date		717,552		754,604
Net underbilled position	$	25,458	$	49,590

Included in the accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts	$	70,643	$	86,734
Billings in excess of costs and estimated earnings on uncompleted contracts		(45,185)		(37,144)
Net underbilled position	$	25,458	$	49,590