I realize I'm a couple of months late on this but I don't believe it's bad luck on Matt's fault. I worked for tech support at a college a year back and saw many hp's come in with this same problem.
The consensus that myself and the other techs came up with is that it's a design problem on HP's part. I can't recall if the dv9000 is the same way but others I have seen have the hard drive(s) placed in the front where most people rest their palms. The structural support there isn't usually enough to prevent the pressure from that from contacting the hard drive. Given enough time and depending on how much you rest your hands/how much pressure you put there, it could cause contact between the shell of the hard drive and the read/write arm and cause damage.
We were able to replicate this with another hard drive and laptop and did end up notifying HP that we were seeing this problem.