So I have a Hitachi 500GB 7200RPM drive in my MBP, and it's lovely. However, it seems that every 3-4 weeks, when I run dis utility and verify disk, it says that I have to restart with the OS X disk in there and repair the disk. What happens during this time when a repair is needed is that the drive starts to make a bit of noise (like the head is parking.) What I believe is happening is that the sudden motion sensor does not work right, because when I move the laptop, the head doesn't park. Is this because I disabled power management on the drives firmware through Hitachi tools? I didn't think power management had anything to do with the sudden motion sensor. After I repair the drive, that "park" noise goes away. I don't think the drive is damaged because everything works smoothly.