I've noticed that for me it only occurs after I've been away from the machine for a while. Often with the lid closed.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/740126 Title: Disabling an output can cause vblank events to be missed -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs