After listening to the sound my hard drive makes every 20 secs or so and doing some research...I have came to the conclusion that the sound is that of the heads parking and unparking. Some say it is a safety feature on the seagate and other hard drives but it is extremely annoying. Does anyone else experience this? It is a clunking type sound every 20 secs or so. So much for a quiet laptop. I have the new 17inch SR MBP with a 7200 rpm 160gb hd. I'm hoping maybe apple can replace the hard drive as I want to keep the computer (no dead pixels, don't want to chance it).