http://bugs.winehq.org/show_bug.cgi?id=20522
--- Comment #4 from Roderick Colenbrander thunderbird2k@gmail.com 2009-11-11 13:59:19 --- I see wined3d (?) performing 24-bit -> 32-bit and 32-bit -> 32-bit. Under the hood we use a ARGB xrender format which preserves an alpha channel when it is around. If I use X8R8G8B8 the app renders properly but then the alpha channel is lost when apps use that which you don't know beforehand. I can't easily say where the real bug is. It might be that I'm not using xrender properly (but I don't think this is the case), so I think the issue is somewhere in wined3d. A log in combination +ddraw,+d3d_surface or so might be useful.