I cannot get the sudden motion sensor working. I went into the terminal and made sure it was turned on, but when I move my computer around the hard drive does NOT lock up like it used to with the stock drive. It makes a wierd whirring noise instead, which makes me concerned. Are apple stock hard drives the only ones that work with the sudden motion sensor for locking up the hard drive upon sudden movement? Aside from making sure the sudden motion sensor is activated in the terminal, is there anything I can do to make it work with the seagate 7200.4 320 gig drive?