I have also had this issue as well. One thing I have noticed is that I can remote in (using ssh) to the box and reboot or shutdown the system. I have not noticed any crashes or pukes in my logs though when this happens. This seems to start happening with every new ubuntu distribution, then goes away (until the next ubuntu release) after a few updates.
Dell E1705 - Ubuntu 9.04, ATI video card. -- [r128 1002:5446] Selecting the Molecule screensaver makes the PC freeze. It is completely unresponsive. https://bugs.launchpad.net/bugs/106060 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-screensaver in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs