unity-window-decorator crashed with SIGSEGV in window_closed()

[MoLE]

Binary package hint: compiz

crashed after update-manager refreshed after completing an upgrade

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: compiz-gnome 1:0.9.4-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-5.32-generic 2.6.38-rc6
Uname: Linux 2.6.38-5-generic i686
Architecture: i386
CrashCounter: 1
Date: Mon Mar 7 20:31:33 2011
ExecutablePath: /usr/bin/unity-window-decorator
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110209)
ProcCmdline: /usr/bin/unity-window-decorator
ProcEnviron:
 LANGUAGE=en_AU:en
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x805bc9b <window_closed+187>: mov 0x224(%eax),%eax
 PC (0x0805bc9b) ok
 source "0x224(%eax)" (0x00000224) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: compiz
StacktraceTop:
 window_closed (screen=0x9316410, win=0x939c540) at /build/buildd/compiz-0.9.4/unity/unity_window_decorator/src/wnck.c:725
 g_cclosure_marshal_VOID__OBJECT () from /usr/lib/libgobject-2.0.so.0
 g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
 ?? () from /usr/lib/libgobject-2.0.so.0
 g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
Title: unity-window-decorator crashed with SIGSEGV in window_closed()
UpgradeStatus: Upgraded to natty on 2011-02-24 (10 days ago)
UserGroups: adm admin audio cdrom dialout dip fax floppy fuse lpadmin plugdev sambashare tape vboxusers video
XsessionErrors: (nautilus:4135): GConf-CRITICAL **: gconf_value_free: assertion `value != NULL' failed

[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 #724874, 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.