https://bugs.freedesktop.org/show_bug.cgi?id=33371
--- Comment #10 from Michel Dänzer michel@daenzer.net 2011-08-04 03:15:04 PDT --- I was able to reproduce the problem, but for me it's fixed with current Mesa Git master and 7.11 branches. Make sure your 32 bit r600g is up to date, though you might also need a newer kernel / X driver.
In the worst case, turning off colour tiling might work around the problem.