I've had my iMac for about a week. I have a quick question about a certain noise. It sounds actually like a harddrive writing stuff, but a little louder, and I would have guessed that was it if it happened intermittently. This noise, however, ONLY and ALWAYS occurs for about 10 min after I start up the iMac and then dies away. What could this be? Any reason except annoyance to get a replacement (if this noise is not meant to be) Could this problem be repaired by a premium reseller with repair service?