Compiz freeze

What I was doing while it happened: Taking a screenshot using default application, alt + prnt scrn, of a libreoffice drawing.

Mouse responsive, system still functional. Able to switch to TTY 6 and killall compiz, which then automatically respawned. Sometimes it doesn't automatically respawn, at which point I need to restart the system, which causes me to lose work.

Compiz freezes during other activities, but this is the first freeze I've reported. I can't pin down a specific behavioral trigger, other than it freezes very definitively upon user input (e.g., clicking a button in a dialogue box, taking a screenshot, switching desktop workspaces, etc).

This error message appeared after the killall, but it might just be a reflection of the killall:

 compiz[2016]: segfault at 11 ip 00000011 sp bfae95bc error 14 in compiz[8048000+c000]

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: compiz 1:0.9.7.12-0ubuntu3
ProcVersionSignature: Ubuntu 3.2.0-61.63-lowlatency-pae 3.2.55
Uname: Linux 3.2.0-61-lowlatency-pae i686
.tmp.unity.support.test.0:

ApportVersion: 2.0.1-0ubuntu17.6
Architecture: i386
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: compiz
Date: Thu May 1 17:17:34 2014
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 0c) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:0209]
   Subsystem: Dell Device [1028:0209]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MachineType: Dell Inc. XPS M1330
MarkForUpload: True
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-61-lowlatency-pae root=UUID=8e1188f1-2cff-41e9-8298-1d4b1983f24d ro quiet splash acpi_backlight=vendor dell_laptop.backlight=0 vt.handoff=7
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/26/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A15
dmi.board.name: 0N6705
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA15:bd12/26/2008:svnDellInc.:pnXPSM1330:pvr:rvnDellInc.:rn0N6705:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: XPS M1330
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.7.12-0ubuntu3
version.libdrm2: libdrm2 2.4.46-1ubuntu0.0.0.1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.4-0ubuntu0.7
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.4-0ubuntu0.7
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu10.14
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu1.2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4.4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build3