Screen Space UI "Moving"?

I have had a pretty game-breaking issue pop up today, my Screen Space - Overlay UI moves horizontally when the camera moves. No other way to describe it, and have no other information than that.

I have a video to show this:
https://drive.google.com/file/d/0BwUnG8MJCX7tU09WZ0U0RFl2SGc/view?usp=sharing