National Guard (search) soldiers fighting in Iraq and Afghanistan are also battling with their own government over long delays and widespread errors in their paychecks, according to congressional auditors.

The General Accounting Office (search) says in a study to be released Thursday that some activated Army National Guard soldiers saw delays of up to three months in their pay while others were overpaid an average of $48,000 and told later they had to pay it back.

Responding to the study, the Defense Department (search) vowed to correct the problems and conduct a broader review to improve the systems involved.

House Government Reform Committee Chairman Tom Davis, R-Va., and Rep. Christopher Shays, R-Conn., sent a letter to Defense Secretary Donald Rumsfeld this week expressing concern that the Pentagon will not aggressively pursue the problem.

And they asked Rumsfeld to monitor the pay issue "because of the magnitude of the problem and our skepticism that systemic military pay and allowance problems can be resolved quickly."

The GAO found that the system used to pay the activated National Guard troops is so cumbersome that soldiers in a number of units were routinely getting over- and underpaid. In case studies, GAO said, 34 Colorado soldiers were overpaid an average $48,000.

In other cases, injured solders were denied active duty pay and medical benefits. A majority of Guard members in a California military police unit saw three-month delays in their pay.

The pay problems, said GAO, "have had a profound financial impact on individual soldiers and their families," adding that many had to spend considerable time trying to correct the errors.

Assistant Army Secretary Sandra Pack, in a letter to Shays, said the problems showed the Pentagon has not lived up to its commitment to the soldiers. And she said the department is "taking concrete steps" to ensure that service members receive accurate and timely pay.

The changes, outlined in a two-page memo, include training and finance classes for pay personnel, better monitoring of those who are on active duty and long-range improvements to the pay systems.

All of the pay problems for specific units identified by the GAO report were also corrected.