[Samba] Password change from WinXP (PAM Error)

[Markus]

Hi,
When I try to change my Password with XP's Password-Change-Box, I get
the following error in log.smbd:
[2004/03/21 11:16:06, 0] passdb/pampass.c:smb_pam_chauthtok(709)
   PAM: UNKNOWN PAM ERROR (19) for User: testuser
[2004/03/21 11:16:06, 0] passdb/pampass.c:smb_pam_passchange(865)
   smb_pam_passchange: PAM: Password Change Failed for user testuser!

 From my smb.conf:
         # PDC
         os level = 65
         domain master = yes
         local master = yes
         preferred master = yes

         # Security
         security = user
         hosts allow = 192.168.1.
         encrypt passwords = yes
         domain logons = yes

         # Roaming profiles/HomeDirs
         logon path = \\%L\%U\profiles
         logon home = \\%L\%U\profiles
         # logon drive = Y:

         # Password change
         obey pam restrictions = no
         pam password change = yes
         passwd program = /usr/bin/passwd %u
         passwd chat = Newpassword* %n Re-enternewpassword %n
*passwd:allauthenticationtokensupdatedsuccessfully
         update encrypted = Yes
         passwd chat debug = yes
         # Additional
         unix password sync = yes
         admin users = markus
         domain admin group = @smbadm
         domain logons = yes
         wins support = yes
         add user script = /usr/sbin/useradd -g machines -c sambaclient
-d /dev/null -s /bin/false %m$
         nt acl support = no
         logon script = login.cmd

Can someone help me please.

Thx
      Markus