At home, I have AirPort Extreme, so I connect to the net with my wireless card. But when I came back to college, I use an ethernet cable, because their wireless network is unreliable. But when I plugged it in, nothing happens, and when I checked Network in System Preferences, the summary only shows AirPort and Internal Modem. How can I get the computer to see the ethernet cable? It was working fine in December before I left. I'm now using their wireless network, but who knows how long it'll stay up.