Help needed.... Perhaps a bug?

[Steve]

Hello,

I have just downloaded PyChess. started playing a quick qame to see how it worked when I suddenly got the following message at the bottom of the screen. "Stephen won because of adjudication by an admin invalid engine move: e8g8". The computer was castling, Neither of the pieces had previously been moved, it wasn't in check, it wasn't passing through check and it wouldn't end up in check. I can't see why the move was invalid.

Perhaps I am missing something? I haven't played in a very long time, Any help gratefully received. I have included a screen-shot.

Thanks

Steve.

[Steve]

Sorry for the double post. The first one hadn't appeared on my screen even after numerous refreshes. When I posted this, both of them suddenly appeared.