samba - Jan 2008 - user must logon to change password

I installed samba-3.0.28 (PDC+tdbsam)
I turned ON the Samba Policy Control "user must logon to change
password" by
runing below pdbedit command:

# pdbedit -P "user must logon to change password" -C 2
account policy "user must logon to change password" description: Force
Users
to logon for password change (default: 0 ==> off, 2 ==> on)
account policy value for user must logon to change password was 0
account policy value for user must logon to change password is now 2

Then I change the password to "pierluigim" with smbpasswd command:
smbpasswd pierluigim

when login from XP prof  as "pierluigim"  .. why did not it ask me to
change
the password .. ?

Can you help me?

Thanks
Andrea