http://bugs.winehq.org/show_bug.cgi?id=16559
--- Comment #27 from W3ird_N3rd mailme667@yahoo.co.uk 2009-06-20 19:19:58 --- Created an attachment (id=21919) --> (http://bugs.winehq.org/attachment.cgi?id=21919) Before/after comparison patch when playing Trickstyle
Thinking about it, R8G8B8A8 does contain an alpha channel. Take everything I say with a truckload of salt, I'm really no expert. There could be a bug either in the code to handle textures with an alpha channel, or the patch from Andrew might contain a bug, or maybe something else - I'm not sure.
I made a screenshot to show the difference in Trickstyle, it speaks for itself.
So bug #18608 (http://bugs.winehq.org/show_bug.cgi?id=18608) is possibly related.