Invoice total and Final balance due on AR invoices don't match

Hello everyone,

I'm hoping someone will be able to help.  Our AR invoices have an additional section at the bottom, beneath the Invoice Total, showing payments/credit/discounts applied, with a Final Balance Due. That way, once someone pays the invoice, it will print out with a zero balance due.

A few weeks ago, my co-worker created a Credit Memo in the amount of $240, out of the Sales Order module.  He printed it on the spot, before updating and doing end of day processing.  When I went back in a few days later to print it for my records and send to the customer, it showed the Invoice Total of ($240) -correct, but with payments applied of $240 - incorrect, and Final Balance Due of ($480) - incorrect.  Please note that when I'm in MAS and looking at it on the screen, it's all correct.

It gets more interesting, as the credit memo has now been used.  When I look at it on the screen, again it's correct - ZERO balance.  Just for fun, I printed it out.  Invoice Total says ($240), payments applied zero, and Final Balance Due ($240).  Hmmmmm.... Does anyone have any thoughts as to why this happened?

Thanks so much for any clues!

Ellen