Win2K Pro Network Problem…

WINNT 4.0 domain…I have a Win98 comp. on the network with a DSL connection and use AnologX as the proxy. When I use one specific comp. this problem machine to browse the internet after about 5 to 15 mins of browsing…the network connection is lost. Win2K seems to re-establish the connection but, I am unable to browse the network. I have to go to the LAN properties and disable the LAN connection and then enable it again.
(Win2K SP2, 3COM FastEther Link XL PCI 10/100, Latest driver installed)

Does anyone know of a solution….