Hmmm... I just re read your first post. I see you are trying to change the material over time. I just tried it, and I can't do it either. I tried it in world space first, and it didn't work, so I tried it in Object space, and then parametric. No dice. I've never tried animating a mat before, I would assume it's possible, but maybe there is, as you say, a bug in the works.