Index: nav-menu.php
===================================================================
--- nav-menu.php	(revision 37802)
+++ nav-menu.php	(working copy)
@@ -78,7 +78,10 @@
 			if ( ! have_posts() )
 				return;
 			while ( have_posts() ) {
-				the_post();
+				global $post;
+				global $wp_query;
+				$post = $wp_query->next_post();
+				setup_postdata( $post );
 				if ( 'markup' == $response_format ) {
 					$var_by_ref = get_the_ID();
 					echo walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', array( get_post( $var_by_ref ) ) ), 0, (object) $args );