Can not download print driver

We have 2 different computers running Windows XP, SP1, unable to add a
printer from a Windows 2000 print server. Other computers can add printers
from this print server, but these 2 problem machines can not add any printer
from this print server. The error that they get when they attempt to do so
is: "The server for the printer does not have the correct printer driver
installed." ...The users have administrator rights on the local computers,
and there is plenty of available space on the local computers. Our
"work-around" is to bypass the print server and use local TCP/IP printing.
Ideas?