Matching Credits to unvalidated or invoices on hold not possible in R12

In R12 it is not possible to match a credit memo to an unvalidated invoice, or to an invoice which is on hold.  However, when the invoice is match to a PO and is unvalidated, and a credit is referencing that same PO Nr, it is possible to match the credit to the invoice.

Is there a workaround (or an overlooked set up step) which allows us to match a credit to an unvalided or on hold invoice?

regards
Reina