unity-2d-shell crashed with SIGSEGV in QDeclarativeObjectScriptClass::newQObject()

dont have idea how to reproduce...Sorry

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity-2d-shell 5.7.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
CrashCounter: 1
Date: Tue Mar 20 18:59:00 2012
ExecutablePath: /usr/bin/unity-2d-shell
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120223.1)
ProcCmdline: unity-2d-shell
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f784aa3edba <QDeclarativeObjectScriptClass::newQObject(QObject*, int)+74>: testb $0x8,0x20(%r15)
 PC (0x7f784aa3edba) ok
 source "$0x8" ok
 destination "0x20(%r15)" (0x100000022) not located in a known VMA region (needed writable region)!
SegvReason: writing unknown VMA
Signal: 11
SourcePackage: unity-2d
StacktraceTop:
 QDeclarativeObjectScriptClass::newQObject (this=0x1d08cf0, object=0x1f00940, type=136) at qml/qdeclarativeobjectscriptclass.cpp:118
 QDeclarativeEnginePrivate::scriptValueFromVariant (this=0x1c40380, val=...) at qml/qdeclarativeengine.cpp:2093
 QDeclarativeObjectScriptClass::property (this=<optimized out>, obj=0x1f762f0, name=<optimized out>) at qml/qdeclarativeobjectscriptclass.cpp:320
 QDeclarativeContextScriptClass::property (this=0x1d08400, object=<optimized out>, name=<optimized out>) at qml/qdeclarativecontextscriptclass.cpp:289
 ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
Title: unity-2d-shell crashed with SIGSEGV in QDeclarativeObjectScriptClass::newQObject()
UpgradeStatus: Upgraded to precise on 2012-03-13 (7 days ago)
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