The walking foot is designed to act like the feed dogs on your machine - i.e., feed the fabric through with a gentle pushing motion. You know how some times when you sew two long pieces together that are the same length, one ends up being a little longer than the other when you are done? It helps keep both pieces even as you sew. It's not for free motion quilting - only for straight line quilting, like stitch in the ditch.
If your walking food it's working correctly then check the presser foot pressure to be sure it's adjusted correctly so the walking foot can push the fabric.