As I unscrewed the Hitachi hard drive in my unibody macbook to take a look at it, I noticed four small bars, two at each side, which are used to hold it . I'm thinking of changing it with a WD scorpio Black. But as I read in the forums, it makes a lot of vibrating noises.. So my thoughts are that those noises are produced because the WD does not have those four "legs" in order to hold it and in order for the "feet-sockets" to absorb the vibrations. I'm not sure if I'm very clear in my description. So my main question. Do other hard drives also have those "feet" or whatever?