Ian T, I am not real sure about your problem, but when I was setting up my home network, I found out that window's doesn't automatically overide the default connection. This means that if you have a modem, and used dial up, you will have to go into the network settings panel and select the icon with the little check mark (right mouse) and turn off the default connection.
But then again, this was my probelm, not sure if it is yours.
(P.S. look in the windows directory and see if you can find the network data log... a network guru would probally LOVE that!)
Merranvo, taking over the net, one forum at a time.