I just purchased a 11.6" macbook air 128gig model and after using it for ~3 hours straight I started hearing something. I turned the TV on mute and noticed the fan is fairly audible. This might make me sound like a noob (which I'm not denying I am), but I didn't even know they put a fan in the air bc its so slim. Now I can confirm there is a fan somewhere around the Q and W key. Is it normal to hear it after using it with no more than web browsing for a few hours?