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

[Jérémy Quentel]

Binary package hint: unity

while configuring the ring switcher in compiz, it crashes

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: unity 3.8.2-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
CrashCounter: 1
Date: Tue Apr 5 22:19:44 2011
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta amd64 (20110405)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=fr:en
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7fa70e9dd2f6 <_ZNK4sigc11signal_base4implEv+22>: mov 0x8(%rdi),%rbx
 PC (0x7fa70e9dd2f6) 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: No upgrade log present (probably fresh install)
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=0x1a68320, screen=0x10c49f0) at /usr/include/sigc++-2.0/sigc++/signal.h:2659
 UnityScreen::UnityScreen (this=0x1a68320, screen=0x10c49f0) at /build/buildd/unity-3.8.2/src/unityshell.cpp:861
 VTableForScreenAndWindow<UnityScreen, UnityWindow>::initScreen (this=<value optimized out>, s=0x10c49f0) at /usr/include/compiz/core/plugin.h:238