Don't load importer using menu loader.

feeds.module

@@ -252,7 +252,7 @@ function feeds_menu() {
     'file' => 'feeds.pages.inc',
     'type' => MENU_LOCAL_TASK,
   );
-  $items['import/%feeds_importer/template'] = array(
+  $items['import/%/template'] = array(
     'page callback' => 'feeds_importer_template',
     'page arguments' => array(1),
     'access callback' => 'feeds_access',

feeds.pages.inc

@@ -201,8 +201,8 @@ function feeds_fetcher_callback($importer, $feed_nid = 0) {
 /**
  * Template generation
  */
-function feeds_importer_template($importer) {
-  $importer = feeds_importer_load($importer);
+function feeds_importer_template($importer_id) {
+  $importer = feeds_importer($importer_id);
   if ($importer->parser instanceof FeedsCSVParser) {
     return $importer->parser->getTemplate();
   }