https://bugs.freedesktop.org/show_bug.cgi?id=29580
--- Comment #2 from Frederic Crozat fred@crozat.net 2010-08-17 00:09:00 PDT --- I've done more tests (with gnome-shell 2.29.1 + clutter 1.2.8): -with Mesa 7.8.2 and KMS disabled, I don't see any pixmap corruption (but gnome-shell become very slow) -with Mesa git and KMS disabled, windows are not visible at all (only the shadow is visible) and gnome-shell is also very slow.
I'll do more tests tomorrow, when gnome-shell git is buildable again, since I think the slowness was fixed in git.