compiz crashed with SIGSEGV in sigc::internal::signal_emit0<void, sigc::nil>::emit()

Hello
Reporting another bug, probably related, https://bugs.launchpad.net/ubuntu/+source/unity/+bug/735331, I click on the older UNE icons and then two firefox icons appear on the unity Launcher, then Compiz crash

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: libnux-0.9-0 0.9.32-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-6.34-generic 2.6.38-rc7
Uname: Linux 2.6.38-6-generic i686
Architecture: i386
Date: Tue Mar 15 09:39:00 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu-Netbook 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=it_IT:it_IT.UTF-8:en
 PATH=(custom, user)
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x67600f0 <_ZN4sigc8internal12signal_emit0IvNS_3nilEE4emitEPNS0_11signal_implE+144>: mov 0x8(%esi),%eax
 PC (0x067600f0) ok
 source "0x8(%esi)" (0x0000007b) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: nux
StacktraceTop:
 sigc::internal::signal_emit0<void, sigc::nil>::emit(sigc::internal::signal_impl*) () from /usr/lib/compiz/libunityshell.so
 Launcher::EventLogic() () from /usr/lib/compiz/libunityshell.so
 Launcher::DrawContent(nux::GraphicsEngine&, bool) () from /usr/lib/compiz/libunityshell.so
 nux::View::ProcessDraw(nux::GraphicsEngine&, bool) () from /usr/lib/libnux-0.9.so.0
 nux::Layout::ProcessDraw(nux::GraphicsEngine&, bool) () from /usr/lib/libnux-0.9.so.0
Title: compiz crashed with SIGSEGV in sigc::internal::signal_emit0<void, sigc::nil>::emit()
UpgradeStatus: Upgraded to natty on 2011-02-22 (20 days ago)
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