[Samba] Samba + Active Directory

[samba_list]

Hi,

I´m having much trouble on configuring Samba to work on an Active
Directory
environment.

Using getent password I´m able to see AD´s users. wbinfo -u and wbinfo -g
also work fine.

When someone from a Windows try to access my Samba server, the smd
password
window is shown (I think that the autehntication would be transparent,
wouldn't it ?), any password I provide is rejected: I tried AD users using
either the plain username and the DOMAIN\username form. I tried also using
my root password, without any success.

The logs are saying:
[2004/01/05 18:42:30, 1] smbd/sesssetup.c:reply_spnego_kerberos(172)
Failed to verify incoming ticket!
[2004/01/05 18:42:30, 1] smbd/sesssetup.c:reply_spnego_kerberos(172)
Failed to verify incoming ticket!

Is there any special configuration I have to do on Active Directory to
become AD authentication available to Samba ?

I´ve already installed PAM and followed all intructions at samba.org,
but is
not working.

Could someone please help me ?

Thanks in advance,

Lindolfo

P.S.: I´ve already checked both servers´ time, they are syncronized.