On an unrelated note, I noticed a bug in the remote_login_js() function of domain_mapping.php regarding an occasional “Unknown logout key” message. Specifically, in the } elseif ( $_GET[ 'action' ] == 'logout' ) { block, there is a $wpdb->prepare( ... ) call that has WHERE id = %d which actually needs to be WHERE id = %s (since the id is an md5 hash).
