Android :: OpenGLES Lighting - Should Not Change Position

I'm writing a little 3D engine for android to better learn the platform and opengl. I hope to eventually use it as a base for little 3D games.

I'm trying to implement lighting right now, and generally following the NeHe opengl android port tutorials. I have a simple spinning cube and 1 light that should not change position. Upon rendering my scene on a device the light appears to "dim" and re-lighten as cube rotates.

This is a swf video of the behavior:
http://drop.io/obzfq4g

The code for my "engine" is located here: [url]
The relevant bits are:

[url]
This is where I'm initializing opengl and setting up my scene. and [url]this is the code for actually rotating / drawing the cube mesh.

I wish I could formulate a better question; but I'm very stuck/confused and can't even think of an intelligent question to ask besides "does anyone know what might cause the kind of behavior I'm seeing?"

Also the slowness / choppyness of the animation in the video is a result of the screencap software. It's smooth throughout the whole rotation on the emu.