Onebyone,
that's the foot I have, it came with my machine. Mine hops because it has the arm that hooks over the needle screw. I usually don't mind the hopping, but if I'm working on a piece that has lots of really small curves, then the hopping action can hinder making the curves smooth, unless I speed up the machine a lot which doesn't work as well when making tiny designs. That's when I switch to the westalee ruler foot-- it doesn't hop at all, but the trade off is slight loss of visibility.
Rob