https://bugs.freedesktop.org/show_bug.cgi?id=45018
--- Comment #10 from Michel Dänzer michel@daenzer.net 2012-01-28 04:52:09 PST --- (In reply to comment #9)
The bugs is not visible under kernel 3.2, [...]
3.2 lacks Radeon virtual address space support.
I will try with a 3.3-rc2 kernel once it will be available.
That's unlikely to make a difference, this is likely a userspace bug.