XP Service Pack 3 causing problems when a user changes their passw

We have a problem here at work since installing Windows XP Service Pack 3.
We have found that when Active Directory asks a user to change their password
and the user does so, when the user logs on it does not load the profile
correctly. It logs them on with a default profile. To get around this you
have to log the user off and restart the computer then log on as
administrator, delete the users local profile and then log off as
administrator and log on as the user. This now works fine. The weird thing
is that we have set DeleteCachedCopiesOfRoamingProfiles to be deleted in
group policy so it should be deleting them but isn't.

Obviously we cannot go around each user each time this happens as we have
over 2000 users! Has anyone experienced the same or similar problem?