This sounds a lot like what I describe in bug #155312. The solution for me was to switch from i810 to the driver called intel.
-- Xorg hangs during idle [gutsy, i810] https://bugs.launchpad.net/bugs/157423 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
