[Samba] authenticating PDC against itself

[alphac]

I need to let squid authenticate against the domain controller but both
samba and squid are running on the same machine, but I cannot get to use
ntlm.

Is it possible do join to the PDC the same machine running the PDC with:
net join -S DOMAIN -U Administrator ?.

wbinfo -p :
Ping to winbindd succeeded on fd 4

wbinfo -g --domain=DOMAIN :
Error looking up domain groups

 wbinfo -a alphac%alphac --domain=DOMAIN :
(doesn't give back the prompt, I have to break with ctrl+c )

>From samba logs the last thing I see is that a the user is autenticating
against samba no errors or anything else.

Thanks
-- 
Guglielmo