The Airport icon in the menu bar is no longer showing the status of Airport, even when the card is functioning correctly. I can surf the internet wirelessly (no ethernet cable plugged into my iMac) and yet the menu bar tells me that I am not connected to any router. What puzzles me most is that the status shown in System Preferences / Network contradicts the menu bar and tells me that my Airport card is up and running. How can I repair this glitch? Thanks.