It does it low when hovering next to me too. I am now thinking its not the camera itself but possibly the gimball. It seems very sensitive and may be giving it that jerk.The playback on my ST16 is pretty jerky as well. I think it's just a playback limitation on the controller and not a problem with the video.
I'm still not convinced it's a problem with the camera. The vibration should not be getting to the camera at all. When you do a hover close to you, can you see vibration in the H and in the camera?