Stevie,
I also think this has to do a lot with the scale of the object, and it's placement inside the 3D space. While your models may indeed be within range of the camera if set to infinity, (I love that; but that's another topic) the scale and cull operations are the source of your troubles. Cull with cut anything effectively too close or large, and scale and placement determine what you can see. Sadly, you have to read over the example much more close in many cases to reproduce the images you see in them.
Patience. It will come, after you gained a few bumps on your head from beating it against the screen.
S.
Any truly great code should be indisguishable from magic.