Hey guys, my hard drive intermittently stalls...Basically, I'll be working on something, and then all of a sudden, my computer will freeze up. When I give the part of my case near my hard drive a nice slap or two, it will usually resume working. What's wrong? Is this user-fixable? Should it be covered under AppleCare? I'm running OS 10.3.8 on a Powerbook G4 12" 1 GHz from right before the March 2004 updates. And no, I didn't drop it.