compiz crashed with SIGSEGV in PrivateWindow::addWindowStackChanges()

[Roger]

Crash happening all by itself. The only window opened after a reboot was Nautilus, and I hadn't yet got around to doing anything else. Fully up-to-date 11.10 Oneiric.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.18.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu2
Architecture: amd64
CrashCounter: 1
Date: Wed Sep 28 18:14:29 2011
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110827)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x43f766 <_ZN13PrivateWindow21addWindowStackChangesEP14XWindowChangesP10CompWindow+38>: mov 0x68(%rdx),%rdi
 PC (0x0043f766) ok
 source "0x68(%rdx)" (0x00000068) not located in a known VMA region (needed readable region)!
 destination "%rdi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 PrivateWindow::addWindowStackChanges(XWindowChanges*, CompWindow*) ()
 CompWindow::lower() ()
 CompScreen::handleEvent(_XEvent*) ()
 PrivateCompositeScreen::handleEvent(_XEvent*) () from /usr/lib/compiz/libcomposite.so
 CompScreen::handleEvent(_XEvent*) ()
Title: compiz crashed with SIGSEGV in PrivateWindow::addWindowStackChanges()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare vboxusers

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #861542, 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.