I also encountered the same problem on newly installed Ubuntu 10.10 (Maverick) x64 on a PC that has Sapphire ATI Radeon HD 4350 512MB DDR2 PCI-E.
uname says: Linux 2.6.35-24-generic #42-Ubuntu SMP Thu Dec 2 02:41:37 UTC 2010 x86_64 GNU/Linux dpkg says: ii xserver-xorg-video-ati 1:6.13.1-1ubuntu5 The problem usually starts very shortly after the system boots and I'm not even able to log in. Soon the system becomes unresponsive. If I boot in recovery mode, I'm able to log in. Putting nomodeset option in GRUB_CMDLINE_LINUX_DEFAULT solved the problem. Another solution I found is explained on https://wiki.ubuntu.com/X/KernelModeSetting . The command for turning off KMS for radeon driver: # echo options radeon modeset=0 > /etc/modprobe.d/radeon-kms.conf -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in ubuntu. https://bugs.launchpad.net/bugs/619365 Title: Screen corruption when X starts _______________________________________________ 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