REOBack Backup Solution

I try to use it on my webspace for local backups. The chmod of reoback.pl and run_reoback.sh are 755. I think the settings are good but it doesn't work. The script start with a cronjob but it only creates the directory in the backups folder. There is nothing to see in the logs. Any ideas? Are there any restriction for the use of reoback on a webspace account?