[Samba] samba pdc issue

[Alessandro]

I have upgrade the pdc server from debian sarge to etch.
After this operation we can't login to the domain (client windows 2000 & 
XP)

smbclient works fine and from a windows local account I can browser the 
samba directories too (puttin username and password before..)
I use tdbsam of course and pdbedit -L let me see all the accounts, it 
seems to work fine

I tried to remove a pc from the domain, and putting it into again, but 
it doesn't works. I tried to create a new user account, but the same it 
doesnt work

What can I do?

Thanks
Alessandro