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

[deuce]

Binary package hint: unity

enabled "Negative" option in compiz config and compiz crashed.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: unity 3.6.4-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-6.34-generic-pae 2.6.38-rc7
Uname: Linux 2.6.38-6-generic-pae i686
Architecture: i386
CrashCounter: 1
Date: Tue Mar 15 15:46:30 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcCmdline: /usr/bin/compiz
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0xb7281e3d <_ZNK4sigc11signal_base4implEv+29>: mov 0x4(%edi),%esi
 PC (0xb7281e3d) ok
 source "0x4(%edi)" (0x0000007c) not located in a known VMA region (needed readable region)!
 destination "%esi" 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 2011-02-26 (16 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

StacktraceTop:
 sigc::signal_base::impl (this=0x78) at ../../sigc++/signal_base.cc:145
 sigc::signal_base::connect (this=0x78, slot_=...) at ../../sigc++/signal_base.cc:122
 connect (this=0xafe1bed8, screen=0x88384b8) at /usr/include/sigc++-2.0/sigc++/signal.h:2659
 UnityScreen::UnityScreen (this=0xafe1bed8, screen=0x88384b8) at /build/buildd/unity-3.6.4/src/unityshell.cpp:753
 VTableForScreenAndWindow<UnityScreen, UnityWindow>::initScreen (this=0x8c41bc8, s=0x88384b8) at /usr/include/compiz/core/plugin.h:238