Can you try the patch at http://people.freedesktop.org/~airlied/radeon_rn50_memmap.diff
And let me know ? -- system freeze when using ati radeon 7000 with xorg "ati" driver https://launchpad.net/bugs/16873 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs