Attached Link: http://www.youtube.com/watch?v=3UK5NzAMxFo&feature=share&list=UUgn8YTaJ36OkdRw449CeUXg

Check the key frames, if there is a problem delete the key frame and then set again.

http://www.youtube.com/watch?v=3UK5NzAMxFo&feature=share&list=UUgn8YTaJ36OkdRw449CeUXg

This is a movie made on that idea some two years  ago I have the movement smoother now as you will see on the other animations.

I must say that Poser and its idiosyncrasies drive me made. You will find one problem after another, but I hate to dump old friends especially when they have been so expensive.