Not sure how else to describe this.
Scenario - one planet and one object (a small moon). Both are textured. The moon is one moon of the planet (Phobos) and in this case needs to be very close to the planet (Mars).
Problem - when Phobos is next to Mars, Phobos loses its texture completely in the render. If I move Phobos back away so that it is too far to be realistic, I get my texture of Phobos back.
The workaround for this was to render each separately and put them together in Photoshop.