Hi Guys, I just got a new 27" 3.2GHz iMac which was about 1 and a half weeks ago. It is making like a crackling sound all the time and is starting to annoy me, I googled it and apparently something to do with the Optical drive if you have one. I do, so I unplugged it (Official Apple Superdrive) and it still remains making the sounds. I recorded a little bit of the sound so you could judge it.. http://vocaroo.com/i/s0ZInjVBwv6Q Does anyone know what it could be? Thanks!