Using the Expansion pack you might notice the rumble buzzes quite loudly at times. This is not a fault of the rumble mechanism, but just of how the pack is put together. For me, I noticed it buzzed whenever I tilted the DS to the right. So I figured out what the deal is: the PCB is slightly loose in the case, so it actually can move right next to the rumble mechanism and the rumble will buzz against the PCB. So I just took a small piece of double sided scotch tape and carefully put it on the chip directly under the battery. Be deliberate in how you place the PCB back down on the plastic casing and make sure the PCB isn't touching the rumble mechanism. Put the casing back together and enjoy silent (as much as it can be) rumble! I also think the video in the review had a rumble mechanism that didn't have the foam padding on it, so that's why it rattles all the time in the review vid. Mine is just as silent as it could be! edit: well, it still rattles a little when set to high, but still only when tilted to the right... something else must be loose I can't figure out what or how to stabilize it. I guess you can say your mileage may vary.