I went through the same thing. Do you notice the cold having an effect on it? I found mine worked fine in warm weather but did exactly what you describe in the cold. I even put it in the fridge to prove it. This is obviously unacceptable for our uses. I tried multiple fixes of my own, but after getting some advice on a GoPro forum that this shouldn't be the case with a solid state piece of equipment I sent it back to GoPro. They sent a new one back pretty quickly with no hassles although I did miss having it on a good trip.
(hint) send it back without the battery in it. If you are lucky like me they'll send the new one back with a battery in it and you'll end up with a spare.
I got it for Christmas, so I've only used it in the cold so far. I was wondering if that had something to do with it. Mine seemed to be affected by vibration too though. I hope they replace it with a good one quickly...