Windows ME Networking Problem

I have a pair of “hybrid” machines I built and have connected to a home network. I have a cable internet connection and both machines and the cable modem are routed through my hub (cable connected to uplink port). My main problem/complaint is that for some weird reason I can only get one machine to connect to the internet at a time, and I cannot see either machine from the other in My Network Places (Network Neighborhood in Win98. I have identical protocols and clients installed on my network. I have inspected all cabling, hub, and ethernet cards and all are in perfect working condition. Whichever computer I turn on and connect to the network first is the only system that can access the internet. Any suggestions??