--- xmlsitemap.admin.inc-old	2010-04-30 05:31:25.000000000 +0200
+++ xmlsitemap.admin.inc	2010-10-20 10:42:11.000000000 +0200
@@ -817,7 +817,10 @@ function xmlsitemap_add_form_link_option
   if (module_exists('ctools')) {
     ctools_include('dependent');
   }
-
+  // In case of menu.module disabled.
+  if (empty($form['#submit']) || !is_array($form['#submit'])) {
+    $form['#submit'] = array();
+  }
   // Add the submit handler to adjust the default values if selected.
   if (!in_array('xmlsitemap_process_form_link_options', $form['#submit'])) {
     array_unshift($form['#submit'], 'xmlsitemap_process_form_link_options');