unity-2d-launcher crashed with SIGSEGV

[UbuntuUser]

Unexpected crash of unity while using firefox.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity-2d-launcher 4.0.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-8.11-generic 3.0.1
Uname: Linux 3.0.0-8-generic x86_64
Architecture: amd64
Date: Sat Aug 20 23:14:48 2011
Disassembly: => 0x30: Cannot access memory at address 0x30
ExecutablePath: /usr/bin/unity-2d-launcher
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
ProcCmdline: unity-2d-launcher
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x30: Cannot access memory at address 0x30
 PC (0x00000030) not located in a known VMA region (needed executable region)!
SegvReason: executing NULL VMA
Signal: 11
SourcePackage: unity-2d
StacktraceTop:
 ?? ()
 ?? () from /usr/lib/x86_64-linux-gnu/libQtDeclarative.so.4
 ?? () from /usr/lib/x86_64-linux-gnu/libQtDeclarative.so.4
 ?? () from /usr/lib/x86_64-linux-gnu/libQtDeclarative.so.4
 ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
Title: unity-2d-launcher crashed with SIGSEGV
UpgradeStatus: Upgraded to oneiric on 2011-08-20 (0 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare vboxusers

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 QDeclarativePropertyCache::property (engine=<optimized out>, obj=0x14b0e20, name=@0x7fff8a0c6918, local=...) at qml/qdeclarativepropertycache.cpp:408
 QDeclarativeObjectScriptClass::queryProperty (this=0x88b740, obj=<optimized out>, name=@0x7fff8a0c6918, flags=<optimized out>, evalContext=0x0, hints=...) at qml/qdeclarativeobjectscriptclass.cpp:167
 QDeclarativeObjectScriptClass::queryProperty (this=0x88b740, object=<optimized out>, name=@0x7fff8a0c6918, flags=<optimized out>) at qml/qdeclarativeobjectscriptclass.cpp:147
 QScript::DeclarativeObjectDelegate::getOwnPropertySlot (this=0x116ebc0, object=0x7f97b8c5adc0, exec=0x7f97c7f53048, propertyName=..., slot=...) at bridge/qscriptdeclarativeobject.cpp:74