nautilus crashed with SIGSEGV in g_type_check_instance_cast()

[Mr.Jack]

Nautilus chrashes whenever i start to Download something via Firefox

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: nautilus 1:3.3.91-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic i686
ApportVersion: 1.94.1-0ubuntu2
Architecture: i386
Date: Wed Mar 14 15:27:24 2012
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/nautilus
GsettingsChanges:
 org.gnome.nautilus.window-state geometry '795x550+0+24'
 org.gnome.nautilus.window-state start-with-status-bar true
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
ProcCmdline: nautilus
ProcEnviron:
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x6ef0e3 <g_type_check_instance_cast+83>: movzbl 0xe(%esi),%edx
 PC (0x006ef0e3) ok
 source "0xe(%esi)" (0xffff010a) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: nautilus
StacktraceTop:
 g_type_check_instance_cast () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
 ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-gtk3.so.4
 g_cclosure_marshal_VOID__VOID () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
 g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
 ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
Title: nautilus crashed with SIGSEGV in g_type_check_instance_cast()
UpgradeStatus: Upgraded to precise on 2012-03-13 (1 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #953509, 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.