X crashes while playing videos

When trying to play videos with Dragon and/or VLC, X keeps crashing. This has only started very recently.

Steps to reproduce :

1) Open VLC/Dragon
2) Try to play a local/remote file
3) X crashes, restarts, and I'm shown the login screen

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xserver-xorg 1:7.6+10ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-12.21-generic 3.2.2
Uname: Linux 3.2.0-12-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: kwin
Date: Thu Feb 2 20:00:35 2012
DistUpgraded: Log time: 2012-01-12 22:31:18.899805
DistroCodename: precise
DistroVariant: kubuntu
GraphicsCard:
 Advanced Micro Devices [AMD] nee ATI Seymour [Radeon HD 6400M Series] [1002:6760] (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00e1]
InstallationMedia: Kubuntu 11.04 "Natty Narwhal" - Release amd64+mac (20110427)
JockeyStatus:
 ERROR:root:Could not find any typelib for AppIndicator3
 xorg:fglrx_updates - ATI/AMD proprietary FGLRX graphics driver (post-release updates) (Proprietary, Disabled, Not in use)
 xorg:fglrx - ATI/AMD proprietary FGLRX graphics driver (Proprietary, Disabled, Not in use)
MachineType: Apple Inc. MacBookPro8,2
ProcEnviron:
 LANGUAGE=en_IN:en
 LC_CTYPE=en_IN
 PATH=(custom, user)
 LANG=en_IN
 SHELL=/bin/zsh
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-12-generic root=UUID=2b916ef1-1a9d-42d2-975d-a14b19cdcfa3 ro nomodeset
SourcePackage: xorg
UpgradeStatus: Upgraded to precise on 2012-01-12 (20 days ago)
dmi.bios.date: 10/14/11
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP81.88Z.0047.B24.1110141131
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-94245A3940C91C80
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro8,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-94245A3940C91C80
dmi.modalias: dmi:bvnAppleInc.:bvrMBP81.88Z.0047.B24.1110141131:bd10/14/11:svnAppleInc.:pnMacBookPro8,2:pvr1.0:rvnAppleInc.:rnMac-94245A3940C91C80:rvrMacBookPro8,2:cvnAppleInc.:ct10:cvrMac-94245A3940C91C80:
dmi.product.name: MacBookPro8,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz N/A
version.fglrx-installer: fglrx-installer N/A
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0~rc2-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0~rc2-0ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.11.3-0ubuntu9
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.99.901-1ubuntu3
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu3
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2