compiz crashed with SIGSEGV in unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent()

[nuk]

I turned my laptop On (Dell XPS15 L502X) and was using it without any problems for about 5 minutes (with dual screen using a dvi-vga adpater).
Suddenly this problem emerged.
My version is Precise 12.04 Beta 2 Installed last Thursday and upgraded manually yesterday.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity 5.10.0-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-20.33-generic 3.2.12
Uname: Linux 3.2.0-20-generic x86_64
ApportVersion: 2.0.1-0ubuntu4
Architecture: amd64
CrashCounter: 1
Date: Wed Apr 18 10:25:08 2012
Disassembly: => 0x0: Não é possível acessar a memória no endereço 0x0
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=pt_BR:pt:en
 PATH=(custom, no user)
 LANG=pt_BR.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x0: Não é possível acessar a memória no endereço 0x0
 PC (0x00000000) not located in a known VMA region (needed executable region)!
 source "0x0" (0x00000000) not located in a known VMA region (needed readable region)!
SegvReason:
 executing NULL VMA
 reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 ?? ()
 unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent(unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent>) () from /usr/lib/compiz/libunityshell.so
 sigc::internal::slot_call2<sigc::bound_mem_functor2<void, unity::ui::EdgeBarrierController::Impl, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >, void, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >::call_it(sigc::internal::slot_rep*, unity::ui::PointerBarrierWrapper* const&, std::shared_ptr<unity::ui::BarrierEvent> const&) () from /usr/lib/compiz/libunityshell.so
 unity::ui::PointerBarrierWrapper::EmitCurrentData() () from /usr/lib/compiz/libunityshell.so
 ?? () from /usr/lib/compiz/libunityshell.so
Title: compiz crashed with SIGSEGV in unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent (this=0x146e9b0, owner=0x28d62c0, event=...) at /build/buildd/unity-5.10.0/plugins/unityshell/src/EdgeBarrierController.cpp:139
 operator() (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1917
 operator()<unity::ui::PointerBarrierWrapper* const&, const std::shared_ptr<unity::ui::BarrierEvent>&> (_A_arg2=<optimized out>, _A_arg1=<optimized out>, this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:103
 sigc::internal::slot_call2<sigc::bound_mem_functor2<void, unity::ui::EdgeBarrierController::Impl, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >, void, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >::call_it (rep=<optimized out>, a_1=<optimized out>, a_2=<optimized out>) at /usr/include/sigc++-2.0/sigc++/functors/slot.h:173

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.