nautilus crashed with SIGSEGV in lookup_iface_entry_I()

Where just working when I got the crash-report.

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: ubuntuone-client-gnome 4.1.91-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-9.18-generic 3.8.1
Uname: Linux 3.8.0-9-generic x86_64
ApportVersion: 2.9-0ubuntu2
Architecture: amd64
Date: Sun Mar 3 14:20:21 2013
ExecutablePath: /usr/bin/nautilus
InstallationDate: Installed on 2013-01-21 (40 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130121)
MarkForUpload: True
ProcCmdline: nautilus -n
SegvAnalysis:
 Segfault happened at: 0x7febe681bde6: mov (%r8),%eax
 PC (0x7febe681bde6) ok
 source "(%r8)" (0xff606060ff616161) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: ubuntuone-client-gnome
StacktraceTop:
 ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 g_type_check_instance_is_a () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 nautilus_file_info_invalidate_extension_info () from /usr/lib/libnautilus-extension.so.1
 file_watcher_update_path () from /usr/lib/nautilus/extensions-3.0/libnautilus-ubuntuone.so
 g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: nautilus crashed with SIGSEGV in g_type_check_instance_is_a()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
XsessionErrors:
 (nautilus:2132): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer
 (nautilus:2132): GLib-GObject-CRITICAL **: g_signal_handler_disconnect: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
 (nautilus:2132): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer
 (nautilus:2132): GLib-GObject-CRITICAL **: g_signal_handler_disconnect: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed