SCAT for Withholding tax update in vendor master

hi

I am getting problem in SCAT for updating the with holding tax view in vendor master

there are different line items of taxes,now system picks single field name for all line items(as filed name is same )

so while updating only single entry can be updated,

if i try to agin update second entry sytem replace first entry with first one

plz let me know how can i tackel the similar filed problem in SCAT

regards

kunal