[Samba] password sync HP/UX 11.00 and samba 2.2.3a

[Seeger, Christof]

Hello everybody,
I am using samba for a couple of years, and I am really happy about it. But
now I have a problem with the password validation on my new 2.2.3a samba
version, which I have to use because I am going to upgrade my clients to
W2K. I want the passwords to be synchronized between the unix and the samba
passwd file. 
I generated the smbpasswd file and changed the users to have the option NO
PASSWORD allowed. After logon to the client, the password in the smbpasswd
file is still set to NO PASSWORD, and the user can log on with any password
he wants, not even using the one which is set in /etc/passwd !!!
In my former version of samba ( 2.05a ) the password was being synchronized
between /etc/passwd and the smbpasswd file, when I had an entry for the user
with the option NO PASSWORD set in the smbpasswd file. I didn´t had to use
the smbpasswd command to set the samba password.
I am sure I´ve made a fault in my smb.conf, but I cannot find it. Here are
the options of my smb.conf file reflecting password validation :

[global]
   encrypt passwords = yes
   null passwords = yes
   guest account = samba
   load printers = yes

    ##### passwd_update #####
   min passwd length = 6
   unix password sync = true
   passwd program = /bin/passwd %u; touch /tmp/pass/%n
   passwd chat = *Changing*password:* %n\n *password:* %n\n *changed*
   update encrypted = yes
   socket options = TCP_NODELAY
   #########################
  share modes = yes
  security = user
  domain master = yes
  preferred master = False
  local master = yes
  domain logons = yes
  logon script = %U.bat
  os level = 65
  workgroup = nl-test
  wins support = no
  time server = yes
  name resolve order = host bcast
  add user script = /usr/sbin/useradd -g machines %m$
 
Hopefully, this is not too confusing, and I hope, that someone can help me. 

best regards

Christof Seeger
Adolf Würth GmbH & Co.KG