We had a new person invoicing and invoiced a SO very wrong one time and then couple days later invoiced it correctly.  The first invoice the qty backordered was entered instead of the qty  shipped and the freight was entered into the discount box.  So after that was posted it ended up showing the we owed the customer the amount that was entered into the discount.  Then a couple days later must have figured out something was wrong and invoiced it correctly by invoicing it with the qty shipped filled in and the freight entered correctly.  So now there is not any backordered items but it still shows that we owe the customer the discount amount that was entered from the first invoice.  Do we just need to do a SO Invoice Data Entry credit memo in the discount field?  These kind of things make my head spin.  :-)  Thanks for any help and advice!