Index: src/wp-includes/nav-menu.php
===================================================================
--- src/wp-includes/nav-menu.php	(revision 27167)
+++ src/wp-includes/nav-menu.php	(working copy)
@@ -357,10 +357,6 @@
 
 	$update = 0 != $menu_item_db_id;
 
-	// Only set the menu term if it isn't set to avoid unnecessary wp_get_object_terms()
-	if ( $menu_id && ( ! $update || ! is_object_in_term( $menu_item_db_id, 'nav_menu', (int) $menu->term_id ) ) )
-		$post['tax_input'] = array( 'nav_menu' => array( intval( $menu->term_id ) ) );
-
 	// New menu item. Default is draft status
 	if ( ! $update ) {
 		$post['ID'] = 0;
@@ -368,6 +364,11 @@
 		$menu_item_db_id = wp_insert_post( $post );
 		if ( ! $menu_item_db_id	|| is_wp_error( $menu_item_db_id ) )
 			return $menu_item_db_id;
+
+		// Associate the menu item with the menu term
+		if ( $menu_id ) {
+			wp_set_object_terms( $menu_item_db_id, array( $menu->term_id ), 'nav_menu' );
+		}
 	}
 
 	if ( 'custom' == $args['menu-item-type'] ) {