voucher is showing as domestic for foreign supplier

Hi all,

we are facing an issue in case of currency code for a particular voucher.please find the following details:

There are are three vouchers for a particular supplier and all of them are in foreign (F). In case of one of these vouchers,it is populating as D as currrency mode even though it should be F.

This may happen if the user over rides the currency code as D after entering the voucher in foreign mode.Apart from this I would like to know what else could be the reason for currency code not populating properly.

Thanks in advance.