Happens on an Ubuntu CD too:

Backtrace was generated from '/usr/bin/users-admin'

Using host libthread_db library "/lib/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 46912582180720 (LWP 13104)]
0x00002aaaae697094 in waitpid () from /lib/libpthread.so.0
#0  0x00002aaaae697094 in waitpid () from /lib/libpthread.so.0
#1  0x00002aaaaac26eea in libgnomeui_module_info_get () from
/usr/lib/libgnomeui-2.so.0
#2  <signal handler called>
#3  gst_xml_element_find_first (parent=0xc0, name=0x41f3a3 "passwd_max_life") at
gst-xml.c:85
#4  0x0000000000416755 in gst_xml_set_child_content (parent=0xc0, child=0x41f3a3
"passwd_max_life", val=0x837980 "0") at gst-xml.c:407
#5  0x0000000000414595 in user_update_xml (node=0xc0, data=0x94c1e0,
change_password=1) at user-group-xml.c:483
#6  0x000000000040e997 in user_update (ud=0x8f9620) at user-settings.c:635
#7  0x000000000040c61e in on_user_settings_ok_clicked (button=) at callbacks.c:451
#8  0x00002aaaac86c3c0 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#9  0x00002aaaac87af2c in g_signal_stop_emission () from
/usr/lib/libgobject-2.0.so.0
#10 0x00002aaaac87c3ec in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#11 0x00002aaaac87c7a3 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#12 0x00002aaaabb0d8a7 in _gtk_button_set_depressed () from
/usr/lib/libgtk-x11-2.0.so.0
#13 0x00002aaaac86c3c0 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#14 0x00002aaaac87aab1 in g_signal_stop_emission () from
/usr/lib/libgobject-2.0.so.0
#15 0x00002aaaac87c3ec in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#16 0x00002aaaac87c7a3 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#17 0x00002aaaabb0ce59 in _gtk_button_paint () from /usr/lib/libgtk-x11-2.0.so.0
#18 0x00002aaaabbc5bc0 in _gtk_marshal_BOOLEAN__BOXED () from
/usr/lib/libgtk-x11-2.0.so.0
#19 0x00002aaaac86c3c0 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#20 0x00002aaaac87b0ab in g_signal_stop_emission () from
/usr/lib/libgobject-2.0.so.0
#21 0x00002aaaac87c127 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#22 0x00002aaaac87c7a3 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#23 0x00002aaaabca3ec5 in gtk_widget_activate () from /usr/lib/libgtk-x11-2.0.so.0
#24 0x00002aaaabbc3fcb in gtk_propagate_event () from /usr/lib/libgtk-x11-2.0.so.0
#25 0x00002aaaabbc4447 in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0
#26 0x00002aaaac144f3c in _gdk_events_queue () from /usr/lib/libgdk-x11-2.0.so.0
#27 0x00002aaaace7a46d in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#28 0x00002aaaace7d60f in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#29 0x00002aaaace7d8ba in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#30 0x00002aaaabbc3830 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#31 0x000000000041aa40 in tool_main_do (tool=) at gst-tool.c:1061
#32 0x000000000040bcf1 in main (argc=) at main.c:254

Thread 1 (Thread 46912582180720 (LWP 13104)):
#0  0x00002aaaae697094 in waitpid () from /lib/libpthread.so.0
No symbol table info available.
#1  0x00002aaaaac26eea in libgnomeui_module_info_get () from
/usr/lib/libgnomeui-2.so.0
No symbol table info available.
#2  <signal handler called>
No symbol table info available.
#3  gst_xml_element_find_first (parent=0xc0, name=0x41f3a3 "passwd_max_life") at
gst-xml.c:85
	node = #0  0x00002aaaae697094 in waitpid () from /lib/libpthread.so.0