Comment 39 for bug 427869

OK people, I am the reason for the re-opening the bug :) (https://bugs.launchpad.net/bugs/461617). So I played a bit with the payment process. I implemented the code from the comment #3 in my original post and I have seen, that the error occurs only when:

1. The invoice currency <> company currency
2. The currency rate changed between the invoice date and payment date.

Accounting process calculates the right write-off amount (currency rate loss/gain is added to the write-off account), only the residual amount on the invoice is (still) wrong. The residual bug is, at least in my case, result of the changed currency rate.