I can only use cron jobs to an external service (eg cronjob.de).
My workarround:
Changes in cloner.cron.php:
####### VERIFY IP ACCESS
/*
$ip_list = @explode("\r\n", $_CONFIG['cron_ip']);
$ip_list[] = $_SERVER['SERVER_ADDR'];
$curent_ip = $_SERVER["REMOTE_ADDR"];
if(!in_array($curent_ip, $ip_list)){
echo "Access Denied for ip $curent_ip!";
exit;
}
*/
#########################
After disable this function I can use exterel cron jobs!
Idee for a new feature:
Disabling IP access control in settings for user with externel cron job.
http://wordpress.org/extend/plugins/xcloner-backup-and-restore/