Have a look at this.
There is indeed something wrong with your ZTP. My best guess as to the problem there are two things:
1. You may have not formatted the TGA files correctly. Using Paint.NET works for me.
2. Many (>4) polygons sharing a vertice is gonna* (probably OK but it can) cause problems, especially if said polygons are to be triangles. Look at the top and bottom of the ball. The system does not know how to share two verts stacked in the center, shared between 32 triangles. As a rule, don't allow that to happen. When making models, always format them in Blender as quads. Sometimes you will need triangles to express a shape, that's OK.
In this file main.c below, focus on line 109. that's where you change the model.
In addition, the ZT model loading demo was causing extra problems because it was trying to animate that model, causing vomit.
I'm sorry you are having so much trouble. Also pay attention to the size of the model. In the demo i provided, it's scaled up by 14 and also you can move closer or farther from it with UP and DOWN.