I'm always on WiFi - even when I don't need to be. I noticed this, and wanted to change that to get the fastest transfer speed while I'm at my desk (and plugged in). So I disconnected Airport and I get the following message: Cable unplugged The cable for Built-in Ethernet is not plugged in. I get this even with the cable plugged directly into the model. My wife's MB works just fine. Does this sound as if my Ethernet card died?