Activity in our allowance for doubtful accounts on accounts and long-term receivables consists of the following:

	Years Ended September 30,
	2011		2010
Balance at beginning of period	$	7,429	$	3,574
Additions to costs and expenses		1,071		7,440
Deductions for uncollectible receivables written off, net of recoveries		(5,795)		(3,585)
Balance at end of period	$	2,705	$	7,429

	Years Ended September 30,
	2011		2010
	Restated		Restated
Accounts payable, trade	$	49,556	$	38,395
Accrued compensation and benefits		11,662		11,315
Accrued insurance liabilities		7,040		6,915
Other accrued expenses		10,722		16,174
	$	78,980	$	72,799

	Years Ended September 30,
	2011		2010
Costs incurred on contracts in progress	$	335,204	$	362,594
Estimated earnings		21,942		47,656
		357,146		410,250
Less--Billings to date		(366,768)		(410,945)
Net contracts in progress	$	(9,622)	$	(695)
Costs and estimated earnings in excess of billings on uncompleted contracts		9,963		14,549
Less--Billings in excess of costs and estimated earnings on uncompleted contracts		(19,585)		(15,244)
Net contracts in progress	$	(9,622)	$	(695)

	Years Ended September 30,
	2011		2010
Deposits	$	3,986	$	6,587
Deferred tax assets		1,040		1,677
Executive Savings Plan assets		477		889
Securities and equity investments		1,003		2,065
Other		581		664
Total	$	7,087	$	11,882

We assessed the fair market value of our investment in EPV after its restructuring in 2009 and determined that it was below its carrying value. Accordingly, we recorded a $2,850 other-than-temporary impairment loss for the year ended September 30, 2009. The total impairment loss is reflected in our Consolidated Statements of Operations as a component of Other Expense and reduced the carrying value of our investment from $3,000 to $150 at September 30, 2009.

On February 24, 2010, EPV filed for Chapter 11 bankruptcy protection. On August 20, 2010, the United States Bankruptcy Court District of New Jersey authorized and approved the sale of substantially all of EPV's assets free and clear of liens, claims, encumbrances and interests to a third-party solar company. As this sale cancelled our claims to our convertible note receivable, we recorded an impairment loss of $150 during the year ended September 30, 2010, which reduced its carrying value to $0.

In April 2000, we committed to invest up to $5,000 in EnerTech. Through September 30, 2011, we have fulfilled our $5,000 investment under this commitment. As our investment is 2% of the overall ownership in EnerTech at September 30, 2011 and 2010, we account for this investment using the cost method of accounting. EnerTech's investment portfolio from time to time results in unrealized losses reflecting a possible, other-than-temporary, impairment of our investment. The carrying value of our investment in EnerTech at September 30, 2011 and 2010 was $1,003 and $2,005, respectively. Our results of operations for the year ended September 30, 2011 includes a write down of $967 attributable to our investment in EnerTech.

The following table presents the reconciliation of the carrying value and unrealized gains (losses) to the fair value of the investment in EnerTech as of September 30, 2011 and 2010:

	Years Ended September 30,
	2011		2010
Carrying value	$	1,003	$	2,005
Unrealized gains (losses)		-		(179)
Fair value	$	1,003	$	1,826

At each reporting date, the Company performs evaluations of impairment for securities to determine if the unrealized losses are other-than-temporary. For equity securities, this evaluation considers a number of factors including, but not limited to, the length of time and extent to which the fair value has been less than cost, the financial condition and near term prospects of the issuer and management's ability and intent to hold the securities until fair value recovers. The assessment of the ability and intent to hold these securities to recovery focuses on liquidity needs, asset and liability management objectives and securities portfolio objectives. Based on the results of this evaluation, we believe the unrealized losses at September 30, 2011 is other than temporary, and have adjusted the carrying value accordingly. As of September 30, 2011 and 2010, the carrying value of these investments was $1,003 and $2,005, respectively. See Note 15, “Fair Value Measurements” for related disclosures relative to fair value measurements.

On December 31, 2010, EnerTech's general partner, with the consent of the fund's investors, extended the fund through December 31, 2011. The fund will terminate on this date unless extended by the fund's valuation committee. The fund may be extended for another one-year period through December 31, 2012 with the consent of the fund's valuation committee.

On May 15, 2006, we received a distribution from the investment in EnerTech of 32,967 shares in Arbinet Corporation. We sold these shares in fiscal 2011; accordingly, the amount of unrealized holding losses included in other comprehensive income at September 30, 2011 and 2010 is $0 and $88, respectively.