I have Poser5 and am trying to make some simple animations. For example, sitting on a couch just until I get the hang of things. I am really struggling with one thing though, and wondered if anyone could explain how to solve it in simple terms?

So, a 30 frame animation, first frame is the default standing pose. 2nd frame, and is a key frame, is my av sitting on a couch, default couch pose in Poser. Last frame, again is a key frame, is the same as the second for looping purposes. Frames in between are small movements of a leg.
My problem is that poser is trying to normalise the movement from frame one to two, so my av is bouncing all over the place. How do I stop this?
Many thanks, Spike