Description of problem:
I was adding widgets to the panel and it happened but recovered also immi.

Version-Release number of selected component:
mate-panel-1.6.1-4.fc20

Additional info:
reporter:       libreport-2.1.9
backtrace_rating: 4
cmdline:        mate-panel
crash_function: g_type_check_instance_is_a
executable:     /usr/bin/mate-panel
kernel:         3.11.10-301.fc20.x86_64
runlevel:       N 5
type:           CCpp
uid:            0

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 g_type_check_instance_is_a at gtype.c:3975
 #1 panel_toplevel_set_name at panel-toplevel.c:4617
 #2 set_tooltip_and_name at drawer.c:308
 #3 g_cclosure_marshal_VOID__STRINGv at gmarshal.c:1004
 #4 _g_closure_invoke_va at gclosure.c:840
 #7 g_settings_real_change_event at gsettings.c:288
 #8 ffi_call_unix64 at ../src/x86/unix64.S:76
 #9 ffi_call at ../src/x86/ffi64.c:522
 #10 g_cclosure_marshal_generic_va at gclosure.c:1550
 #11 _g_closure_invoke_va at gclosure.c:840