Index: wp-admin/admin-ajax.php
===================================================================
--- wp-admin/admin-ajax.php	(revision 21992)
+++ wp-admin/admin-ajax.php	(working copy)
@@ -16,13 +16,16 @@
 define( 'DOING_AJAX', true );
 define( 'WP_ADMIN', true );
 
+/** Load WordPress Bootstrap */
+require_once( dirname( dirname( __FILE__ ) ) . '/wp-load.php' );
+
+/** Allow for cross-domain requests (from the frontend). */
+send_origin_headers();
+
 // Require an action parameter
 if ( empty( $_REQUEST['action'] ) )
 	die( '0' );
 
-/** Load WordPress Bootstrap */
-require_once( dirname( dirname( __FILE__ ) ) . '/wp-load.php' );
-
 /** Load WordPress Administration APIs */
 require_once( ABSPATH . 'wp-admin/includes/admin.php' );