http://bugs.winehq.org/show_bug.cgi?id=29647
--- Comment #13 from Alex Richardson alex.richardson@gmx.de 2012-05-27 11:01:00 CDT --- I managed to run it perfectly with r600g driver. Definitely an upstream issue then.
Sadly this will probably never be fixed for me, since AMD wants to drop r600/700 support very soon. I just hope open source drivers catch up performance-wise soon since other games are not really playable with them