Please include the fix listed at https://bugs.freedesktop.org/show_bug.cgi?id=2164 in upcoming xorg releases, unless it is merged upstream. It will fix the problems with R200 cores on PowerPC computers. (If you check the patch it is obvious that this is a bug :) I have tested it with xorg-x11-6.8.1.904 on a Pegasos G4 with a Radeon 9100 (R200 QM)
Added to 6.8.2