https://bugs.freedesktop.org/show_bug.cgi?id=63599
--- Comment #31 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #30)
I've set each register values from fglrx-console.data and call xinit. Lockup again, nothing changes.
Does the patch in comment 29 fix the issue for you? That patch is upstream now and should be in most stable kernels as well.