I have the exact same problem with X taking 100% CPU after sitting idle for a while. If this is the case for you, then you are most likely experiencing bug 109507 and bug 120347.
-- ubuntu randomly freezes https://bugs.launchpad.net/bugs/117651 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
