Looks like you have hybrid graphics. You probably need to blacklist whatever kernel driver you're not using, or switch the unused video chip off in bios if it lets you.
** Package changed: xserver-xorg-video-intel (Ubuntu) => linux (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/775462 Title: [Arrandale] Xorg freeze (hybrid graphics) -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
