Hey ryn, it looks like this is happening because the low poly edges are too far away from the high poly edges. If you imagine shooting a ray from the side of the low poly from the cage object, you can see how it would miss the high poly object entirely. This sort of thing would work for an organic shape that is smooth shaded because then the ray would be angled inwards towards the edge as the normal gets blended, but for hard surface objects where the rays will always fire perpendicular from the face, this will cause problems.
