gnome-panel crashed with SIGSEGV in g_type_check_instance_cast()

[mattmyers83]

Binary package hint: gnome-panel

Ubuntu 9.04. Gnome panel crashed after opening 20 programs

ProblemType: Crash
Architecture: i386
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/gnome-panel
NonfreeKernelModules: fglrx
Package: gnome-panel 1:2.25.91-0ubuntu3
ProcCmdline: gnome-panel
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 11
SourcePackage: gnome-panel
StacktraceTop:
 g_type_check_instance_cast ()
 ?? () from /usr/lib/libwnck-1.so.22
 ?? () from /usr/lib/libwnck-1.so.22
 ?? () from /usr/lib/libglib-2.0.so.0
 g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
Title: gnome-panel crashed with SIGSEGV in g_type_check_instance_cast()
Uname: Linux 2.6.28-8-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

StacktraceTop:IA__g_type_check_instance_cast (type_instance=0xaaaaaaaa,
set_item_text (mi=0x8d30678, text=0xb62d185e "Mi_nimize")
update_menu_state (menu=0x8d521c8)
g_idle_dispatch (source=0x8a24510, callback=0xaaaaaaaa,
IA__g_main_context_dispatch (context=0x87e68c0)

[Martin Mai (mrkanister-deactivatedaccount-deactivatedaccount)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please answer these questions:

* Is this reproducible?
* If so, what specific steps should we take to recreate this bug?

This will help us to find and resolve the problem.