I got the 13" Pro from that big fella in the red suit who lives up north. So far so good with the computer but if I pick it up fast or jostle it around, I hear this clicking type noise coming from the area of the hard drive. I have been told that this is a sensor locking down the hard drive before the computer falls and hits the floor for example and is nothing to worry about. Is this the case? Again, it only happens when I give the computer a quick movements and once it happens, I can't reproduce the sound until the computer has been still for a while which makes sense if this is a safety feature. Also, I can only get the computer to "click" when the screen/lid is open and the computer is awake which also backs up the safety feature explanation. I just want to make sure I have nothing to worry about. My 2008 white Macbook will not make this clicking sound but I have been told that is will but you just can't hear it. My guess is the aluminum amplifies the sound a bit. Thanks all. I appreciate it.