I keep reading about people getting iMacs with really loud fans. I have a 17" 1.8 on the way (ordered a week ago, shipped yesterday), so I'm wondering, is this really a common problem, or does it just seem that way because probably way more people post about loud fans than about quiet fans? Does anyone have an estimate? I guess I would send it back or whatever you do if you get one with loud fans, but I dunno if I should be seriously worried or not. I know there's no point in worrying but I guess I'm just curious.