http://bugs.winehq.org/show_bug.cgi?id=22779
--- Comment #3 from matejcik@gmail.com 2010-06-19 08:10:07 --- i have experienced very similar glitches in Linux-native port of Unreal Tournament (the old one) with OpenGL renderer, so i must assume that it's a driver bug :(
(in UT, switching texture detail from High to Medium removes the glitches)