wnck-applet crashed with SIGSEGV in g_closure_invoke()

[rufat]

Binary package hint: gnome-panel

I add "applet desktop switch", then I try to config number of virtual desktop's and applet crushed.

ProblemType: Crash
DistroRelease: Ubuntu 10.04
Package: gnome-panel 1:2.30.0-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-20.30-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-20-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Sat Apr 17 09:41:59 2010
ExecutablePath: /usr/lib/gnome-panel/wnck-applet
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100406.1)
ProcCmdline: /usr/lib/gnome-panel/wnck-applet --oaf-activate-iid=OAFIID:GNOME_Wncklet_Factory --oaf-ior-fd=26
ProcEnviron:
 LANG=ru_RU.utf8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x405ab9: mov (%rbx),%rax
 PC (0x00405ab9) ok
 source "(%rbx)" (0x00000000) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: gnome-panel
StacktraceTop:
 ?? ()
 ?? ()
 g_closure_invoke ()
 bonobo_closure_invoke_va_list ()
 bonobo_closure_invoke ()
Title: wnck-applet crashed with SIGSEGV in g_closure_invoke()
UserGroups: adm admin cdrom dialout lpadmin netdev plugdev sambashare
XsessionErrors:
 (polkit-gnome-authentication-agent-1:1501): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (gnome-terminal:1611): Gtk-CRITICAL **: gtk_accel_map_unlock_path: assertion `entry != NULL && entry->lock_count > 0' failed

[Apport retracing service (apport)]

StacktraceTop:
 wncklet_connect_while_alive (object=0x0,
 display_properties_dialog (
 g_closure_invoke ()
 bonobo_closure_invoke_va_list (
 bonobo_closure_invoke (closure=0x7fbdbab5f9c8,