Something for others to watch out for...in the user authentication setup DO NOT select to use active directory and specify the hostname as your AD server! Messes up the security token attached to the PDC and Kerberos and AD wouldn't start anymore...as a result no logons were possible. Took me a couple of loooong days to fix!
Just don't do it ! The NetBIOS hostname field is for the Astaro machines NetBIOS hostname, not the servers. Suggest you use the internal interfaces hostname, if you have assigned one... Otherwise, make one up. ie: asl or astaro or intgateway or whatever.