I've just recently purchased a MacBook Air, and needed to give a presentation. With my previous MacBook, I simply connected, and voila! When I hooked up the Air, there projector didn't register it at all. (There was a PC laptop there, and I just copied onto it with a flash drive, so the day was not lost.) I am now very afraid that the next time I try to present something somewhere, the same problem may occur! Does anyone know what I need to do? I know this may seem like a relatively stupid question, but I can't find the answer in the manuals etc.... Thank you very much for any help!