I have finally set up my envelopes and thought "good, animation time" just to see that I was wrong. I select a controller, I key it at frame 0, I move ahead a few frames, I change it's position/rotation and set a key again. The key icon on the bottom turns red and I think everything is ok. But when I go back to the first keyframe, the position/rotation doesn't go back to the one I keyed initially, and that key icon is yellow. But if I look in the Animation fcurve editor, the curves seem to show that the two keyframes are different, and they are dotted lines. I don't know if this means anything. Please help! Thanks!