RSS feedsThe supplier's investigation has shown that a software upgrade was inadvertently given to PCs not intended to receive it, which made them stop working.
A spokewoman for the department said that the crash only caused delays in dealing with new and amended claims, with regular pensions and benefits payments continuing unaffected.
The department is now considering options including the deduction of service credits and the recovery of damages from its supplier.
Liberal Democrat work and pensions secretary Steve Webb condemned the latest problems.
'It seems that scarcely a week goes by without another example of a government computer system, overseen by well paid consultants, leaving people's finances in a mess,' he said.
EDS today decided to terminate its shareholder rights plan next year.
It said the move would offer 'greater flexibility' for any potential takeover proposals, according to The Times.
Around 40,000 computers within the Department for Work and Pensions were unable to access their network last month when an IT technician incorrectly installed a software upgrade.
EDS said the service disruption at the DWP, which lasted four days at the end of November, was caused by the installation of the software upgrade on machines where it was 'not scheduled for deployment'.
Microsoft and EDS run the DWP's network as part of a £2bn IT contract.
