Tamino Backup with argbatch

I tried to install a batch backup of my customers database with argbatch:

argbatch backup database target=saturn product=tamino database=DBName user=administrator password=adminpassword

where saturn is my node name. I got the following error message from argbatch:

"Command started at: 2002-04-23 10:02:22
Target saturn is unknown (saturn possibly not registered as IP Address in hostli
st)!

Error on read: (ARG0115) Host has closed connection

Command ended at: 2002-04-23 10:02:25"

Even I registered my node (saturn) in the host file and also tried it directly with just providing the IP address I got this message.
Backuping from the Tamino Manager works fine.

If I provide the full hostname taken from the managed hosts list it does not work.

Any idea?