Allows you to set custom order for custom post types. Requires: 'supports' => array('page-attributes'),

gistfile1.php

function my_custom_archive_order( $vars ) {
  if ( !is_admin() && isset($vars['post_type']) && post_type_supports($vars['post_type'], 'page-attributes') ) {
    $vars['orderby'] = 'menu_order';
    $vars['order'] = 'ASC';
  }