Erm... that was sad. Pawn up the whole game, then failed to convert by just moving back and forth. And finally a very weird end game bug I have not seen before.
Well at least a bug detected that should not be too hard to fix. Something positive out of it. :)
(there seems to be a bug with the chesspublisher, it does not remove the rook after 23. ... exd1=Q+, just ignore it :)