98 PC's cannot log into 2000 Domain

Situation.

One NT4 server(PDC and only server) running exchange 5.5.
Upgraded to Server 2000.

Added additional 2000 server to replace old one. Installed
Exchange 5.5, ran dcpromo to create additional DC. Made
global catalog server so we could eventually upgrade to
Exchange 2000.

Swapped IP addresses of servers so router could send mail
to new server. Reason for this was there is no way to
reconfigure router to modify route for inbound email.

Problem,

Windows 98 PC's can no longer log in to the domain.
Message is "The domain password you supplied is not
correct, or access to your logon server has been denied."

Everything i have found on MS's site does not address this
problem.