It's not the 1394 connection, is it, thats causing the problem?
This is a firewire connection and presumably you have a firewire network in control panel > network connections > 1394 ( firewire ) network. It should have nothing to do with your broadband connection and is there for when you need to use a firewire network.
If you don't use one, right click it in network connections and disable it. See if that makes any difference.