Ticket #18882: 18882.patch

wp-admin/js/postbox.dev.js

@@ -45 +45 @@
                                                 postboxes.pbhide( box );
                                 }
                                 postboxes.save_state(page);
+                                postboxes._mark_area();
                         });
 
                         $('.columns-prefs input[type="radio"]').click(function(){