Index: wp-includes/nav-menu-template.php
===================================================================
--- wp-includes/nav-menu-template.php	(revision 18463)
+++ wp-includes/nav-menu-template.php	(working copy)
@@ -169,8 +169,12 @@
 
 	// If no menu was found or if the menu has no items and no location was requested, call the fallback_cb if it exists
 	if ( ( !$menu || is_wp_error($menu) || ( isset($menu_items) && empty($menu_items) && !$args->theme_location ) )
-		&& $args->fallback_cb && is_callable( $args->fallback_cb ) )
+		&& $args->fallback_cb && is_callable( $args->fallback_cb ) ) {
+			if ( 'wp_page_menu' == $args->fallback_cb ) 
+				$args->walker = '';
+
 			return call_user_func( $args->fallback_cb, (array) $args );
+	}
 
 	// If no fallback function was specified and the menu doesn't exists, bail.
 	if ( !$menu || is_wp_error($menu) )