System calculating more withholding taxes(/401) after Upgrade to ECC 6.0

Hi,

We upgraded from ECC 5.0 to 6.0. Though 'Allowances' are entered in Infotype 210 ( say 2 or 3), when payroll is run, it seems to be changing to 0 and deducting more Federal taxes . We want to know if others had the same issue and if SAP has reommended any Note to fix this issue. Pl let us know.

Thanks in advance,

Niranjan