i got my 17"MBP a few days ago and used it for about two nights now. okay, it's a little too hot to place on my lap sometimes but this 17" machine is going to be used as a desktop most of the times anyways. one thing that bothers me though, is a constant, low frequency buzz that is emitted from the logic board area under the left speaker grill. is this normal? i don't think i ever heard this coming from my powerbook. i'm mostly up during nights (7pm-6am... around there) because of my job, and the buzzing gets to me sometimes. is this something the apple geniuses will take a look at?