Hi,
Are you getting Arrears in the Earnings side. if so ask your client if they change any salary components in It 0008 for salary hike. this will give automatically retro run from the date of master data change. if it is not necessary for run from 01.05.2013 on-wards delete those dates in PU03 and run the payroll. No arrears or carry forward amounts will come.
regards,
praneeth kumar