https://bugs.freedesktop.org/show_bug.cgi?id=38270
--- Comment #23 from Gregor Galwas g.galwas@highantdev.de 2011-07-02 07:30:31 PDT --- (In reply to comment #21)
Above might be gentoo specific but anyway I suggest you to check what's in /usr/lib[64]/dri and what `make install` (or whatever you use to install mesa) do on your system.
You were right. There was something wrong with the system. Being uptodate now with drm/ddx/mesa gives me NO MORE corruption with colortiling.