try this PPA. it helped with my probs deb http://ppa.launchpad.net/xorg-edgers/ppa/ubuntu karmic main
then do a dist-upgrade notice: install ppa-purge at first! if you can't get to X again, you might have no internet connection (wifi) so the best would be to first dist- upgrade, then downgrade via ppa-purge, and then dist-upgrade again, then all packages are in /var/cache/apt/archives and can be installed with ppa-purge without a internet connection from their website: !!!!!!!!To revert to official packages, you can install the ppa-purge package and run "sudo ppa-purge xorg-edgers". Note that you will want to reinstall linux-libc-dev afterwards manually if you had libdrm-dev installed on karmic and newer!!!!!!! website: https://launchpad.net/~xorg-edgers https://launchpad.net/~xorg-edgers/+archive/ppa -- After logging out, trying to switch user, and changing from vtty back to X system completely hangs with a black screen with ATI Mobility Radeon non-free Drivers https://bugs.launchpad.net/bugs/500056 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
