Description of problem:
Clicking gmenu-simple-editor on gnome panel menu applet, gnome-panel crashes.

(gdb) bt
#0  0xb7f73402 in __kernel_vsyscall ()
#1  0x05e1ce5e in __lll_mutex_lock_wait () from /lib/libc.so.6
#2  0x05daf028 in _L_lock_43 () from /lib/libc.so.6
#3  0x05da8ecd in ptmalloc_lock_all () from /lib/libc.so.6
#4  0x05dd25c0 in fork () from /lib/libc.so.6
#5  0x00b81c00 in fork () from /lib/libpthread.so.0
#6  0x00162d42 in libgnomeui_segv_handle (signum=6) at gnome-ui-init.c:844
#7  <signal handler called>
#8  0xb7f73402 in __kernel_vsyscall ()
#9  0x05d6fd39 in raise () from /lib/libc.so.6
#10 0x05d71391 in abort () from /lib/libc.so.6
#11 0x05da409b in __libc_message () from /lib/libc.so.6
#12 0x05dab5b7 in _int_free () from /lib/libc.so.6
#13 0x05daeaac in free () from /lib/libc.so.6
#14 0x00aee5f1 in IA__g_free (mem=0x86c7590) at gmem.c:187
#15 0x00ad8ac9 in IA__g_error_free (error=0x86c87d8) at gerror.c:125
#16 0x08088f3b in panel_menu_bar_invoke_menu (menubar=0x858f810, 
    callback_name=0x85b3db0 "edit") at panel-menu-bar.c:483
#17 0x00621139 in IA__g_cclosure_marshal_VOID__VOID (closure=0x86787f8, 
    return_value=0x0, n_param_values=1, param_values=0xbff61dec, 
    invocation_hint=0xbff61cfc, marshal_data=0x8071f70) at gmarshal.c:77
#18 0x00613f0b in IA__g_closure_invoke (closure=0x86787f8, return_value=0x0, 
    n_param_values=1, param_values=0xbff61dec, invocation_hint=0xbff61cfc)
---Type <return> to continue, or q <return> to quit---
    at gclosure.c:490
#19 0x00624d73 in signal_emit_unlocked_R (node=0x858e120, detail=0, 
    instance=0x86ac508, emission_return=0x0, instance_and_params=0xbff61dec)
    at gsignal.c:2438
#20 0x0062626f in IA__g_signal_emit_valist (instance=0x86ac508, signal_id=154, 
    detail=0, var_args=0xbff6202c "�-\212") at gsignal.c:2197
#21 0x00626429 in IA__g_signal_emit (instance=0x86ac508, signal_id=154, 
    detail=0) at gsignal.c:2241
#22 0x008a2e54 in IA__gtk_widget_activate (widget=0x86ac508)
    at gtkwidget.c:3932
#23 0x007985a8 in IA__gtk_menu_shell_activate_item (menu_shell=0x8623178, 
    menu_item=0x86ac508, force_deactivate=1) at gtkmenushell.c:1024
#24 0x00799b72 in gtk_menu_shell_button_release (widget=0x8623178, 
    event=0x86254a0) at gtkmenushell.c:630
#25 0x00791745 in gtk_menu_button_release (widget=0x8623178, event=0x86254a0)
    at gtkmenu.c:2619
#26 0x0078b8a0 in _gtk_marshal_BOOLEAN__BOXED (closure=0x8490b00, 
    return_value=0xbff62220, n_param_values=2, param_values=0xbff622fc, 
    invocation_hint=0xbff6220c, marshal_data=0x7916a0) at gtkmarshalers.c:83
#27 0x006126f9 in g_type_class_meta_marshal (closure=0x8490b00, 
    return_value=0xbff62220, n_param_values=2, param_values=0xbff622fc, 
    invocation_hint=0xbff6220c, marshal_data=0xb4) at gclosure.c:567
#28 0x00613f0b in IA__g_closure_invoke (closure=0x8490b00, 
---Type <return> to continue, or q <return> to quit---
    return_value=0xbff62220, n_param_values=2, param_values=0xbff622fc, 
    invocation_hint=0xbff6220c) at gclosure.c:490
#29 0x006253c3 in signal_emit_unlocked_R (node=0x8492420, detail=0, 
    instance=0x8623178, emission_return=0xbff624bc, 
    instance_and_params=0xbff622fc) at gsignal.c:2476
#30 0x00626037 in IA__g_signal_emit_valist (instance=0x8623178, signal_id=44, 
    detail=0, var_args=0xbff62540 "X%���Tb\bx1b\bO/\212") at gsignal.c:2207
#31 0x00626429 in IA__g_signal_emit (instance=0x8623178, signal_id=44, 
    detail=0) at gsignal.c:2241
#32 0x0089eaa8 in gtk_widget_event_internal (widget=0x8623178, event=0x86254a0)
    at gtkwidget.c:3901
#33 0x00784d43 in IA__gtk_propagate_event (widget=0x8623178, event=0x86254a0)
    at gtkmain.c:2187
#34 0x00785f47 in IA__gtk_main_do_event (event=0x86254a0) at gtkmain.c:1421
#35 0x005520fa in gdk_event_dispatch (source=0x847c1f0, callback=0, 
    user_data=0x0) at gdkevents-x11.c:2320
#36 0x00ae7342 in IA__g_main_context_dispatch (context=0x847c238)
    at gmain.c:2043
#37 0x00aea31f in g_main_context_iterate (context=0x847c238, block=1, 
    dispatch=1, self=0x845cdf8) at gmain.c:2675
#38 0x00aea6c9 in IA__g_main_loop_run (loop=0x856ba90) at gmain.c:2879
#39 0x007863c4 in IA__gtk_main () at gtkmain.c:1000
#40 0x08060807 in main (argc=5, argv=0xbff62844) at main.c:94


Version-Release number of selected component (if applicable):
2.15.90-1.fc6

How reproducible:
always

Steps to Reproduce:
1. click menu edit on gnome-panel menu applet
2.
3.
  
Actual results:


Expected results:


Additional info:
gnome-menus-2.15.90-1.fc6