unity-2d-launcher crashed with SIGSEGV in QScriptValue::engine()

[Step Schwarz]

Binary package hint: unity-2d

1) Ubuntu Natty (development branch); 11.04

2) unity-2d-launcher:
  Installed: 3.6.2-0ubuntu1
  Candidate: 3.6.2-0ubuntu1
  Version table:
 *** 3.6.2-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ natty/main i386 Packages
        100 /var/lib/dpkg/status
     3.6.2-0ubuntu1~bzr456 0
        500 http://ppa.launchpad.net/unity-2d-team/unity-2d-daily/ubuntu/ natty/main i386 Packages

3-4) Was in Update Manager (started via GNOME Do). Update Manager occasionally opens blank windows, which in turn open icon-less squares in the launcher. I believe this _may_ have triggered the crash. The launcher was hidden at the time so I don't know exactly what was happening over there.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: unity-2d-launcher 3.6.2-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-7.35-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
Architecture: i386
CrashCounter: 1
Date: Fri Mar 18 09:09:14 2011
ExecutablePath: /usr/bin/unity-2d-launcher
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcCmdline: unity-2d-launcher
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7d8dd06 <_ZNK12QScriptValue6engineEv+6>: mov (%eax),%edx
 PC (0x07d8dd06) ok
 source "(%eax)" (0x0000000f) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity-2d
StacktraceTop:
 QScriptValue::engine() const () from /usr/lib/libQtScript.so.4
 ?? () from /usr/lib/libQtDeclarative.so.4
 ?? () from /usr/lib/libQtDeclarative.so.4
 ?? () from /usr/lib/libQtDeclarative.so.4
 ?? () from /usr/lib/libQtDeclarative.so.4
Title: unity-2d-launcher crashed with SIGSEGV in QScriptValue::engine()
UpgradeStatus: Upgraded to natty on 2011-03-18 (0 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
XsessionErrors: (Do:2441): Wnck-CRITICAL **: wnck_set_client_type got called multiple times.

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #730545, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.