Sloppy payroll management of the Army has resulted in overpayments to troops of over $55 million, including $188,700 to a lieutenant colonel after she was discharged and $185,000 in active-duty pay to a reservist over two years, according to a new audit.

Just as bad: The Government Accountability Office also found that some soldiers were underpaid by the Army, which manages a $47 billion payroll, in fiscal year 2011. While no overall total was given, they gave an example of a colonel in the Army National Guard who experienced repeated underpayments over 28 years, including hardship duty pay.

A bipartisan coalition of House and Senate members have seized on the new report to demand changes to the Army payroll system.

"We have an obligation to ensure that taxpayers' money is well spent, but we also have a duty to men and women of our armed forces to ensure they receive prompt, accurate pay," said Rep. Darrell Issa, chairman of the House Oversight and Government Reform Committee. "If a soldier is getting underpaid because of a payroll error, that's something that needs to be corrected--immediately," added Sen. Claire McCaskill, Missouri Democrat.

The biggest error found was bonus overpayments of nearly $30 million, though the Army disputed the GAO's finding. Next was $6 million in special pay to those who didn't deserve it, including two who were AWOL--absence without leave.

Some $6 million is being investigated by the Army as fraud, mostly for wrongful claims for housing allowances.