samba - May 2004 - My win98 clients can't change their autentication passwords

Hi all

Hi use Samba as pdc with 50 win98 clients...
when the user tryies to change the password for domain autentication (in Control
Painel, Passwords, Change the Windows Passoword), a message says the PDC Server
was not found...

my settings, in smb.conf is :

encrypted passwords = yes
update encryped = no
unix password sync = yes
smb passwd file = /etc/samba/smbpasswd
passwd program = /usr/bin/passwd
passwd chat = *new*password* %n\n *new*password* %n\n *changed*
passwd chat debug = no


I'm using Samba 2.2.8a on Mandrake 9.2

Someone can help me ?

Thanx in advance...

Hwoarang