password change in a wlan environment

dear wlan gurus, for you maybe a simple question:

we have a couple of wlan connected xp notebooks in our w2k3 ad. the
users of these clients frequently ask to reset their ad-account
passwort. so we go to 'ad user and computer'-mmc and reset the users
password to an inital passwort and chose -> user must change password
at next logon.

then the user starts his notebook and enter the old (cached) password.
when trying to connect to a ressource the users is asked to enter the
old password and to enter a new one. but he can never fullfill this as
the system does not the accept the new passwords. no problems when
doing the same thing wired.

is there a problem when reseting the password wlan'ed ?

any ideas
tim