[Dovecot] dovecot + winbind problem

[Gregorics Tamás]

Hi!

I'm having some problem with our setup. I have a linux server 
authenticating from a win2k3 domain controller via winbind and pam. When 
i try to log in I receive the following error messages:

Jul  3 10:26:10 zeusz pam_winbind[20375]: user 'tamas' granted access
Jul  3 10:26:10 zeusz pam_winbind[20375]: user 'tamas' OK
Jul  3 10:26:10 zeusz pam_winbind[20375]: user 'tamas' granted access
Jul  3 10:26:10 zeusz dovecot: auth(default): userdb(tamas,127.0.0.1): 
user not found from userdb
Jul  3 10:26:10 zeusz dovecot: imap-login: Internal login failure: 
user=<tamas>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured

But when i try other services which also use winbind via pam (like 
popa3d) i can log in without any problem.

Any ideas?