BuddyPress.org

Fixed, so far, by doing this:

Created a directory called _inc under themes/my theme and copied in ajax.php and global.js from bp-default/_inc

Put this in your theme/functions.php
/* Load the AJAX functions for the theme */
require_once( TEMPLATEPATH . ‘/_inc/ajax.php’ );

/* Load the javascript for the theme */
wp_enqueue_script( ‘dtheme-ajax-js’, get_template_directory_uri() . ‘/_inc/global.js’, array(‘jquery’) );