http://bugs.winehq.org/show_bug.cgi?id=22987
--- Comment #24 from Vincent Povirk madewokherd@gmail.com 2010-06-20 01:05:20 --- I maintain that Wine isn't doing anything wrong, and the other programs are broken.
However, Wine could work around it by preferring PIXMAP over image/bmp when both are available. Based on the code, I would expect Wine to already be doing this, so there's also something happening that I don't understand.
So it's a bug in the sense that Wine could be modified to improve the situation, but not in the sense that Wine is broken.