Hi did you find a solution for this?
I had the same problem and spent almost two days trying to solve it. Reading everything I could, recreating the tutorials, etc.
I finally figured out that even though it would load the scene in the Unity editor, it just went to a default looking screen in Android.
It turns out that the second scene that I was loading had Unity OnGUI controls/camera etc. I was able to figure out that NGUI sort of "broke" when I changed cameras?
So I copied the camera in the first scene to the second scene and also created some NGUI controls like a button/sprite and it worked fine in Android. Good luck!
