compiz crashed with SIGSEGV in sigc::signal_base::impl()

[Claudio Moretti]

Binary package hint: unity

Release: Natty 11.04
compizconfig-settings-manager 0.9.4-0ubuntu2
I tried enabling the shift switcher plugin; when clicking it notified me about a conflict with an Expo keyboard shortcut; I chose to disable the shift switcher shortcut and before enabling the switcher compiz crashed.
I disabled the shift switcher and when I clicked on the checkbox compiz crashed again.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: unity 3.6.8-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic x86_64
NonfreeKernelModules: nvidia wl
Architecture: amd64
CrashCounter: 1
Date: Wed Mar 30 13:07:10 2011
ExecutablePath: /usr/bin/compiz
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f500d26b2f6 <_ZNK4sigc11signal_base4implEv+22>: mov 0x8(%rdi),%rbx
 PC (0x7f500d26b2f6) ok
 source "0x8(%rdi)" (0x000000e8) not located in a known VMA region (needed readable region)!
 destination "%rbx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 sigc::signal_base::impl() const () from /usr/lib/libsigc-2.0.so.0
 sigc::signal_base::connect(sigc::slot_base const&) () from /usr/lib/libsigc-2.0.so.0
 UnityScreen::UnityScreen(CompScreen*) () from /usr/lib/compiz/libunityshell.so
 CompPlugin::VTableForScreenAndWindow<UnityScreen, UnityWindow>::initScreen(CompScreen*) () from /usr/lib/compiz/libunityshell.so
 CompManager::initPlugin(CompPlugin*) ()
Title: compiz crashed with SIGSEGV in sigc::signal_base::impl()
UpgradeStatus: Upgraded to natty on 2011-03-29 (0 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

StacktraceTop:
 sigc::signal_base::impl (this=0xe0) at ../../sigc++/signal_base.cc:145
 sigc::signal_base::connect (this=<value optimized out>, slot_=...) at ../../sigc++/signal_base.cc:122
 connect (this=0x1084e00, screen=0x6dd9f0) at /usr/include/sigc++-2.0/sigc++/signal.h:2659
 UnityScreen::UnityScreen (this=0x1084e00, screen=0x6dd9f0) at /build/buildd/unity-3.6.8/src/unityshell.cpp:777
 VTableForScreenAndWindow<UnityScreen, UnityWindow>::initScreen (this=<value optimized out>, s=0x6dd9f0) at /usr/include/compiz/core/plugin.h:238