Using R03B620 Convert Unapplied Receipts to Credit Memos

When using R03B620 it produces Credit Memos for every Receipt transaction for an Unapplied Receipt rather than just producing one Credit Memo for the Open Amount of the Unapplied Receipt.

eg:Unapplied Receipt created for $1000

     Allocated $200   ---- Open Amount now$800

Run R03B620 and it produces 2 Credit Memo Documents - one for $1000-  and one for $200

---- why does it not just create 1 Credit Memo Doc for $800-  ???