Network issues with SP2 when server is Win 98SE.

Four system computer network.
1 Server: Win98SE (client needs DOS for legacy polling)
1 Workstation: Win98SE
2 Workstations: WinXP

One XP workstation installed SP2 - connection to the Win98SE Server is gone. Third party s/w vendor said, not their problem and to uninstall XP2. MS has several options to uninstall - client chose [add/remove] from the control panel.

Connection to the server is still not working from the XP workstation after SP2 uninstalled....

suggestions?

~mrpickle~