- Patch #645758 by Dave Reid: system_settings_form() should set a high weight for buttons.

modules/system/system.module

@@ -2501,6 +2501,7 @@ function _system_settings_form_automatic_defaults($form) {
 function system_settings_form($form, $automatic_defaults = TRUE) {
   $form['actions']['#type'] = 'container';
   $form['actions']['#attributes']['class'][] = 'form-actions';
+  $form['actions']['#weight'] = 100;
   $form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Save configuration'));
 
   if ($automatic_defaults) {