I have had y air a few days now. I have a couple of saved movies, they are avi files and 700mg. They run fine on my pc, yet on the air the videos have lag. Its not too bad but def noticeable. Its a 700mg avi file, why would he air have problems playing something my old 1ghz laptop played without problems. Making me consider getting the new pro. I have to mention that it always happens after 5 mins of watching it, the fan comes on and it slows down, even moving the mouse lags. Is my air faulty or do they all slow under any form of strain?