samba - Jul 2003 - Cannot change user`s passwd from WinXP on Samba-LDAP-PDC

Hi everyone, I have a Samba 2.2.8.a + OpenLdap 2.0.25-1 as a PDC, on Red Hat 
8, with kernel-2.4.18-14. 

First of all I can change the user`s password from my samba box doing:
  [root@samba sbin]# ./smbldap-passwd.pl user.a
  
But, I`m getting an error when doing [ctrl]+[alt]+[Del]/Change password on 
WinXP logged to my domain as user.a, that says:
 
 "Username or password are incorrect. the password letters must be written 
  using upper and lower cases correctly"

And I`m pretty sure my old password is right.

This is what my log.mypc looks like at log level = 100

[2003/07/30 18:18:42, 10] smbd/chgpasswd.c:dochild(211)
  Invoking '/usr/local/sbin/smbldap-passwd.pl user.a' as password change
program.  [2003/07/30 18:18:42, 2] smbd/chgpasswd.c:expect(271)
  expect: Input/output error
[2003/07/30 18:18:42, 3] smbd/chgpasswd.c:talktochild(302)
  Response 1 incorrect
[2003/07/30 18:18:42, 3] smbd/chgpasswd.c:chat_with_program(363)
  Child failed to change password: user.a
[2003/07/30 18:18:42, 3] smbd/chgpasswd.c:chat_with_program(408)
  The status of the process exiting was 512



These are the entries of user.a on the ldap:
[root@samba sbin]# ./smbldap-usershow.pl user.a

dn: uid=user.a,ou=Users,dc=ibm,dc=com
cn: user.a
uid: user.a
uidNumber: 1003
gidNumber: 100
homeDirectory: /home/user.a
loginShell: /bin/bash
gecos: System User
description: System User
objectClass: top
objectClass: account
objectClass: posixAccount
objectClass: sambaAccount
pwdLastSet: 0
logonTime: 0
logoffTime: 2147483647
kickoffTime: 2147483647
displayName: System User
acctFlags: [UX]
rid: 3006
primaryGroupID: 1201
homeDrive: U:
smbHome: \\Samba\homes
profilePath: user.a
scriptPath: user.a.cmd
lmPassword: E3838B5677E9BDD9AAD3B435B51404EE
ntPassword: 4141E0BD0D4FB910A1C3D7BB5510D615
userPassword:: e1NNRDV9N2ZXcW5hUXc1ZWg0alVKbVg5TFgrUkUzWm9zPQ=pwdMustChange:
2147483647
pwdCanChange: 0

I`m using this 3 lines for password sync:
  unix password sync = yes
  passwd program = /usr/local/sbin/smbldap-passwd.pl %u
  passwd chat = *New*password* %n\n *ReType*new*password* %
n\n*passwd:*all*authentication*tokens*updated*successfully*



pd: see the attach  for my smb.conf