(nods to Incarnadine) Aye, there is no sunlight, and the volumes are spots, but your tip about occlusion is good too. What I'm getting at is that, in this project/scene file, NO volumetrics are working. At all. It doesn't matter where I put them, but they will not work in this scene no matter what I do. Thus, the "bug" part of it. I saved off the lamp and loaded it into it's own, empty scene. And boom, the volumetrics worked! But it still doesn't fix my bug...