Xorg crashed with SIGSEGV in _Unwind_Backtrace()

[dust]

just crashed while i wanted to close firefox

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: xserver-xorg-core 2:1.10.4-1ubuntu4.2
Uname: Linux 3.0.0-15-generic i686
.tmp.unity.support.test.1:

Architecture: i386
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Sun Dec 25 01:32:02 2011
DistUpgraded: Log time: 2011-10-14 17:47:14.441693
DistroCodename: oneiric
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu
GraphicsCard:
 ATI Technologies Inc 3D Rage IIC AGP [1002:475a] (rev 7a) (prog-if 00 [VGA controller])
   Subsystem: ATI Technologies Inc Rage 3D Pro AGP 2x XPERT 98 [1002:0084]
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
LiveMediaBuild: Lubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
Lsusb:
 Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 002: ID 045e:003b Microsoft Corp. SideWinder Game Voice
MachineType: MSI MS-6380E
ProcCmdline: /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -background none
ProcEnviron:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-15-generic root=UUID=35e4a079-2f0d-4374-949a-2e3e94ed54ec ro quiet splash vt.handoff=7
Renderer: Software
SegvAnalysis:
 Segfault happened at: 0xf67b19: cmpw $0xb858,(%edx)
 PC (0x00f67b19) ok
 source "$0xb858" ok
 destination "(%edx)" (0x00000219) not located in a known VMA region (needed writable region)!
SegvReason: writing NULL VMA
Signal: 11
SourcePackage: xorg-server
StacktraceTop:
 ?? () from /lib/i386-linux-gnu/libgcc_s.so.1
 _Unwind_Backtrace () from /lib/i386-linux-gnu/libgcc_s.so.1
 backtrace () from /lib/i386-linux-gnu/libc.so.6
 xorg_backtrace ()
 mieqEnqueue ()
Title: Xorg crashed with SIGSEGV in _Unwind_Backtrace()
UserGroups:

dmi.bios.date: 04/02/01
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 07.00T
dmi.board.name: MS-6380E
dmi.board.vendor: MSI
dmi.board.version: 1.0
dmi.chassis.asset.tag: 0123ABC
dmi.chassis.type: 3
dmi.chassis.vendor: Uknown Chassis Manufacture
dmi.chassis.version: Version 1.00
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr07.00T:bd04/02/01:svnMSI:pnMS-6380E:pvr1.0:rvnMSI:rnMS-6380E:rvr1.0:cvnUknownChassisManufacture:ct3:cvrVersion1.00:
dmi.product.name: MS-6380E
dmi.product.version: 1.0
dmi.sys.vendor: MSI
version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu6
version.libdrm2: libdrm2 1:2.4.22-2u1~ppa3
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3
version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #852967, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.

[dust (hannes-b)]

the other bug is marked as private so you 1st need to make it public!