Cboucher: That is what I suspect. Problem is that the network ppl keep insisting that this could not be related to them. Probably they just do not know at what to look at. Could this be a policy enhanced directly on the Active Directory user profile? If that is a possibility, it may sound like it because some users are still able to. Others are not.
Tech3211: They do change passwords once in a while. In such case, they log out completely from the network completely and log back in. As for the net use lpt1 /d, thanks for this reminder. Indeed, that was tried.
PS: Gents, I know of this official note stating that only Admin users should be able to net use to a network printer: http://support.microsoft.com/default...&Product=winxp
(So eventhough they are not Local Admins, probably --- somewhere --those who are still able to net use the network printers are somehow Admins. And those who are not able to were perhaps removed from that Admin group - Thanks for correcting me if I am wrong).
Again, Many thanks foryour generous help.