OMG, this just happened to my com yesterday!! Hdd suddenly failed and made some strange noise.....and i sent to for repair today, and guess what, the guy sitting next to me also had the same problem!!!

something fishy is going.....first was the Palm rest, then Random Shutdown, then flickering screen, and now screwed up harddrive........basically the whole com is f**ked......Macbook is one of the worst product Apple has ever release.....