Phantom Vision pitch control problem

[Ergoadams]

Here is the setup:

Phantom 2 Vision with 3D Power Brushless Gimbal controlled through Simple BGC board.

The set up worked fine for a while. Then I started getting this problem with the camera erratically pitching and becoming unstable.

When I power the Phantom up, the camera/gimbal is steady with no erratic behavior. When I power it up with no blades on it and move it around by hand, it is absolutely normal. Then when I fly it, it starts the pitching behavior.

Any help is appreciated.

I have two videos. The first is powered on, no blades, handheld movement of the Phantom.
The second video is full power and acceleration. This is where you see the issue.

 

[Ergoadams]

I just realized that one of the videos is the wrong one. The first video is blades on but not powered up. The video that I meant to post (no blades, motors powered up) shows the same thing: a 100 percent functional gimbal.