[Samba] NT4.0 SP6 can't connect to Samba 3.0.22

[Den]

I have a Samba 3.0.22 server running as
   security = user
   encrypt passwords = no
and WinNT 4.0 service pack 6 with plain text password.

WinNT4 client can't connet to Samba 3.0.22 server:
[2006/06/13 10:26:55, 3] smbd/negprot.c:reply_negprot(579)
  Selected protocol NT LM 0.12
[2006/06/13 10:27:00, 5] auth/auth.c:make_auth_context_subsystem(489)
  Making default auth method list for security=user, encrypt passwords = no
[2006/06/13 10:27:00, 5] auth/auth.c:check_ntlm_password(271)
  check_ntlm_password: unix authentication for user [brusok] FAILED with
error NT_STATUS_WRONG_PASSWORD
[2006/06/13 10:27:00, 2] auth/auth.c:check_ntlm_password(317)
  check_ntlm_password:  Authentication for user [brusok] -> [brusok] FAILED
with error NT_STATUS_WRONG_
[2006/06/13 10:27:00, 5] auth/auth_util.c:free_user_info(1485)
  attempting to free (and zero) a user_info structure
[2006/06/13 10:27:00, 10] auth/auth_util.c:free_user_info(1488)
  structure was created for brusok
[2006/06/13 10:27:00, 3] smbd/error.c:error_packet(146)
  error packet at smbd/sesssetup.c(1063) cmd=115 (SMBsesssetupX)
NT_STATUS_LOGON_FAILURE

But the same user can connect to Samba 3.0.22 server from WinXP.