Ubuntu can't connect to SambaPDC

Hi guys.

This is not really an OpenLDAP question, but it seems we have some fine qualified users here, so I'll ask this question here. :)

I have a nice working Zentyal 2.2 server with DNS and SambaPDC. Windows client's can join the domain with the network users ans they see all the shared folders too. My problem is that I don't know how to join a domain with Ubuntu.

Tried with likewise-open and likewise-open-gui, but all the time, it sais Bad_DNS_Package. Same error message comes when I try to join from terminal with the command "*sudo domainjoin-cli join DOMAIN USER*" I also installed samba, smbclient, winbind on the client. I heard that it could be because the server is set to allow Win clients only. Could that be?

Thanks in advance!

Imi