Due to an error in interest calculation by the IRS, refunds are being delayed (at least at my institution). They were supposed to pay out by August 31st. Here is the update from Northwestern:

August 15, 2012 - STATUS UPDATE
The IRS has been processing FICA refund claims on a quarterly basis. To date, some of McGaw Medical Center's quarters have been processed, however, there are still several quarters that have not been completed. During a recent inquiry with the IRS, we learned that the IRS has identified an error in their interest calculation. As a result they have stopped processing while they work to resolve this software issue.

Unfortunately, the IRS cannot provide an estimate of how long this process will take. Once McGaw Medical Center receives the remaining data they will issue refunds immediately.

Zip Code: 15228