I just created an invoice for eight items with a shipping discount of $17.71
When I finished, I found TWO invoices listed. One is #319448, with zero in the Purchases Total and $-17.71 as the invoice total, somehow generated four minutes before I finished. The correct invoice was also created, Invoice #319449, which has the correct shipping discount, correct invoice amount, and my note to the buyer at the bottom.
I sent a note to the buyer to ignore the one with the negative balance, and, of course, apologized.
Not a show-stopper, but troubling, so I'm reporting it.