WIthholding Tax TAB is not appearing in F-53,F-58

Hi SAP Gurus,

we are on SAP ECC 6.0  and if we execute all post withclearing transaction like f-53 or F-58 only following tabs are appearing

Standard

Partial Payment

Residual Item

and Withholding tax tab is not appearing, we have checked in SHDO and Withholding tax code having progrmamme SAPDF05X and screen 6105  and it is appearing there

please help us out where changes have to made to activate this TAB as due to supression of this TAB our end users have to make Witholding tax calculation manual which is tedious job

BR

Sajida