I've recently bought an 20" iMac, about 2 weeks ago. It's my first one, so I'm still quite a newbie when it comes to specifics about it. My question isn't really about a big issue, but i would just want to ask if the ocasional, instantaneous and small cooling noise that comes from the left of the computer, after a few hours of continuous use, is normal. It's not a big deal, and it has few appearences, but still, I would like to know. Thanks for your time, and pardon my ignorance.