Hi, I just registered here to ask a question. I bought an iMac in 2009 from the Apple Store (core 2 duo). Ever since the first time I turned it on, I have been hearing a rattling noise from what seems to be the hard drive. It is a constant rattling sound, and you can really hear it when you click something or open something. It is only noticeable when the room is dead silent - when the air conditioner is on, I can't hear it. Is this normal? Should I have it replaced/looked at? Should I upgrade to a Solid State Drive for a quieter experience? The model of my hard drive is: ST31000528ASQ Thanks.