I just tried something like that in C6Pro and it didn't Un-Pose, so to speak, the previous pose at each key frame. It did however a strange type of dance, again so to speak, as it was moving from one pose to the other, kind of funny really, but I don't have C7Pro so it may be an issue with it.
Sorry I can't help.

I would rather be Politically Incorrect,
Then have Politically Correct-Incorrectness!!!