My MacBook Pro (MacBookPro6,2, Intel Core i5, 2.53 GHz) when picked up, makes a clunk from the HD area. Is this normal? I've never heard it on any other machines I've had, including one identical model. Applecare they said it's the sudden motion sensor parking the heads. I said no other machine I've had makes such a loud clunk when doing this. They've replaced the hard drive and drive cable, but it's still the same. Should I be worried? Anyone else have this? It's a small thing but really annoys me. :-/ Can it be fixed?