Maybe this is of interest to somebody - a different solution was shown there. Instead of commenting out DRI or lowering the AGP speed in the BIOS, add Option "AGPMode" "8" to the device section of the graphics card in the xorg.conf.
-- [regression][rv280] black screen and console freeze when X starts - drm lockup https://launchpad.net/bugs/67487 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
