commit dd9df169196441717498ac09ee8c437fb552116e
Author: Vincent Untz <vuntz@gnome.org>
Date:   Sun Oct 11 16:32:53 2009 -0400

    [capplet] Destroy the main window on close to ensure changes are saved
    
    For some reasons, sometimes it works, and sometimes it doesn't. By
    destroying the window, we make sure all objects are disposed and the
    changes are saved.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=597623

diff --git a/capplet/main.c b/capplet/main.c
index c8829a0..861e36a 100644
--- a/capplet/main.c
+++ b/capplet/main.c
@@ -70,6 +70,7 @@ dialog_response (GsmPropertiesDialog *dialog,
                         gtk_widget_destroy (d);
                 }
         } else {
+                gtk_widget_destroy (GTK_WIDGET (dialog));
                 gtk_main_quit ();
         }
 }