Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.440.2.36
diff -u -p -r1.440.2.36 system.module
--- modules/system/system.module	14 Aug 2008 00:13:19 -0000	1.440.2.36
+++ modules/system/system.module	30 Sep 2008 07:21:28 -0000
@@ -1112,16 +1112,17 @@ function system_theme_settings_submit($f
  */
 function system_settings_form_submit($form_id, $form_values) {
   $op = isset($form_values['op']) ? $form_values['op'] : '';
+  $array_filter = isset($form_values['array_filter']);
 
   // Exclude unnecessary elements.
-  unset($form_values['submit'], $form_values['reset'], $form_values['form_id'], $form_values['op'], $form_values['form_token']);
+  unset($form_values['submit'], $form_values['reset'], $form_values['form_id'], $form_values['op'], $form_values['form_token'], $form_values['array_filter']);
 
   foreach ($form_values as $key => $value) {
     if ($op == t('Reset to defaults')) {
       variable_del($key);
     }
     else {
-      if (is_array($value) && isset($form_values['array_filter'])) {
+      if (is_array($value) && $array_filter) {
         $value = array_keys(array_filter($value));
       }
       variable_set($key, $value);