I'm experiencing a similar problem (see this thread: http://www.ubuntuforums.org/showthread.php?t=193283) wherein after anything between 30 mins and 2 hours of using Ubuntu Dapper, Xorg's CPU usage will increase and hit 100%, whereupon the only thing I can do reliably is to hit Ctrl-Alt-Bksp and login again.
I've noticed that when using Xgl instead of Xorg, the same thing happens with the Xgl process. I'm using the 2.6.15-25-686 kernel, with Nvidia drivers from repos. -- Xorg process freezes, uses 100% of CPU. Can be killed by remote terminal. https://launchpad.net/bugs/51991 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
