Win 98 machines lock users account will still logged in.

I've got a hand full of 98se machines which I've loaded so
software on it that only a these user can get. But for
some reason the users will come in and find that using
their correct password to login the machine gives them a
message "the domain password you supplied is not correct,
or access to your logon server had been denied". Then all
they need to do is reboot and use the same password and it
lets them in. Once they get logged in they can get to the
software, but it seems like sometime later they try to get
into the same software and they can't I go check to see if
they are locked on the server and sure enough they are.
Any help would be cool. Thanks in advance