Android : App passed null surface error, when startPreview() is called from onCreate

I have been following the direct camera control tutorial from the academy. The camera activates on button press, but when I moved it to a new activity and call it from onCreate, I need to add an onClick listener for it to activate.

It should be noted, that I am using an AsyncTask to open the camera.

Has anyone encountered this before? Any help is greatly appreciated, as I've been stuck on this for two days now!