Credit Memo no longer functions when processing exchange

Since we've been upgraded, we can no longer process exchanges correctly.

When Nick helped out all those months ago when there were complaints about not seeing credit card numbers any longer, we followed his steps with GREAT success (i.e. creating Return Authorization from the Cash Sale, which populated the credit card number, to be charged or credited amounts relating to the exchange.)  We had virtually no problems with processing refunds after his help.

We then had some help from Barry, who showed us how to turn our Cash Sales Orders into invoices, to properly process exchanges, and use credit memos to apply credits to the open invoices. If there was a remainder to be refunded to the customer, it could be refunded directly from the credit memo to the customer's credit card. The P/N number and the customer's credit card information properly populated, and we virtually had no problems with processing these refunds.