http://bugs.winehq.org/show_bug.cgi?id=3848
------- Additional Comments From oliver_stieber@yahoo.co.uk 2005-18-11 07:33 ------- The black bit is because the back buffer is being used to render textures, I've got a fix to checkin sometime this week.
There's a simpler demo that has some very similar shader problems, fixing that may help this problem, failing that I'm going to do a blitz shaders in a week or so.
Thanks for the other info, I'll stop banging my head trying to fix the white textures and start submitting bug reports to ATI.