I haven't experienced it. Are you running any graphics kernel modules, such
as the NVIDIA or AMD proprietary drivers? What version of Ubuntu are you
on? I recall that such a bug used to exist in the Intel Graphics Stack for
Ivy Bridge GPUs, but it has since been fixed. I'm not quite sure which
kernel version the fix was released with, but I think that Precise is still
affected.
I haven't experienced it. Are you running any graphics kernel modules, such
as the NVIDIA or AMD proprietary drivers? What version of Ubuntu are you
on? I recall that such a bug used to exist in the Intel Graphics Stack for
Ivy Bridge GPUs, but it has since been fixed. I'm not quite sure which
kernel version the fix was released with, but I think that Precise is still
affected.