Comment 6 for bug 716147

I am running 10.04, with an HP laptop plus an external Dell monitor and see this issue frequently, in some cases within an hour of boot. I am not running VMware, but am running VirtualBox. But the problem is occurring in the host OS (Ubuntu 10.04). The problem appears to me to be load dependent as it typically happens when the system is quite busy.

As noted above work arounds for Bug #492782 do not work. In fact logging out causes the screen to go black and the system to not respond to any kbd/mouse input. Only reboot fixes the problem.

For me the bug seems to happen much more frequently (like within an hour of boot) when the external monitor is configured to be the "left" monitor instead of the "right" monitor.

For me, there are no obvious error messages in /var/log/messages or /var/log/Xorg.n.log for the bug. However, system performance becomes degraded and sluggish (e.g. very poor streaming audio/video) making the system unusable.