Win98 RD client no longer able to connect to XP Pro

I have a client that has a WINDOWS 98SE Laptop. He has been using the laptop
for years to connect to a handful of XP Pro computers using the Win98 RD
Client.

Suddenly he is getting the message "The client could not connect to the
remote computer ..." on about 50% of the computers he tries to connect to.
These are computers that he was previously able to connect with.

If I try to connect to these unreachable machines using an XP box I am able
to make the connection.

Nothing has changed on his end, and the connections are actually saved as
shortcuts (I have tried re-creating them on the fly, but this didn't help).
Has some windows update occurred on the remote machines that blocks Win98
connections?

Any ideas on how to correct this (he doesn't want to upgrade his laptop).

Thanks