Comment 14 for bug 772925

Same problem here, running Unity.
Had it after upgrading from 10.10 so I performed a fresh install and problem persists.
If I switch to a VT and kill compiz then I go back to my desktop and compiz restarts and the desktop resumes operability. Therefore I assume problem is related to compiz. Not sure though.
$lspci -v
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 03) (prog-if 00 [VGA controller])
 Subsystem: Toshiba America Info Systems Device 0002
 Flags: bus master, fast devsel, latency 0, IRQ 46
 Memory at ffc00000 (64-bit, non-prefetchable) [size=1M]
 Memory at e0000000 (64-bit, prefetchable) [size=256M]
 I/O ports at cff8 [size=8]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: <access denied>
 Kernel driver in use: i915
 Kernel modules: intelfb, i915

$lsb_release -a
Distributor ID: Ubuntu
Description: Ubuntu 11.04
Release: 11.04
Codename: natty

$uname -r
2.6.38-8-generic

Bug has been reported more then 2 months ago. Please advice course of action for troubleshooting. More than happy to help find the cause of the issue.

Regards,
José