After watching your video, I think I also spotted my problem, didn't realise that every bone requires it's own keyframe on it's own timeline, whether you're trying to control it, moving or not.
I noted you like to select all the bones that you think you are going to need, at the beginning, what happens after a couple of hours of input, you discover one misbehaving bone, that wasn't part of the original selection.
again thanks for the links to the toots, very clear.
Moth