functions.php

<?php

/**
 * Sort post archives by menu order
 *
 * To be used in conjunction with CMS Page Order and https://gist.github.com/2758065
 * 
 * @author Bill Erickson
 * @link http://www.billerickson.net/customize-the-wordpress-query/
 * @param object $query data
 *
 */
function be_post_archive_query( $query ) {

	if( $query->is_main_query() && ( $query->is_home() || $query->is_archive() ) ) {
		$query->set( 'orderby', 'menu_order' );
		$query->set( 'order', 'ASC' );
	}

}

add_action( 'pre_get_posts', 'be_post_archive_query' );