Comment 2 for bug 1304388

StacktraceTop:
 default_app_changed (button=0xa6c6cd8, self=0xa0be350) at cc-info-panel.c:803
 g_cclosure_marshal_VOID__VOID (closure=0xa71ab58, return_value=0x0, n_param_values=1, param_values=0xbf944990, invocation_hint=0xbf94493c, marshal_data=0x0) at /build/buildd/glib2.0-2.40.0/./gobject/gmarshal.c:85
 g_closure_invoke (closure=0xa71ab58, return_value=return_value@entry=0x0, n_param_values=1, param_values=param_values@entry=0xbf944990, invocation_hint=invocation_hint@entry=0xbf94493c) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
 signal_emit_unlocked_R (node=node@entry=0xa67a700, detail=0, instance=0xa6c6cd8, emission_return=emission_return@entry=0x0, instance_and_params=0xbf944990) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3551
 g_signal_emit_valist (instance=instance@entry=0xa6c6cd8, signal_id=signal_id@entry=355, detail=detail@entry=0, var_args=var_args@entry=0xbf944acc "\200\026H\267\220\214p\n\220\264p\n\001") at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3307