No errors in any of the log files. If you move aside your /etc/X11/xorg.conf are you still able to reproduce the freeze?
When the system is frozen, can you ssh into the computer? If so, please collect 'sudo dmesg > dmesg.txt' and your /var/log/kern.log and attach to this bug report. Also, which screensaver package are you using? The 3D screensavers were removed from the version of GNOME included in 12.04; are you using xscreensaver? ** Summary changed: - system freeze with 3D screensaver + [RV370] system freeze with 3D screensaver ** Changed in: mesa (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/946822 Title: [RV370] system freeze with 3D screensaver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/946822/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs