g-s-d
does 

if (!gnome_rr_screen_refresh (screen, &error){
     str = g_strdup_printf (_("Could not refresh the screen information: %s"), error->message);

in handle_fn_f7

but the documentation of gnome_rr_screen_refresh states:
Returns : 	 TRUE if the screen's configuration changed; otherwise, the function returns FALSE and a NULL error if the configuration didn't change, or FALSE and a non-NULL error if there was an error while refreshing the configuration.

Though this error gets dereferenced while beeing NULL.


Thanks, Andres