I have had this happen on my babylock. First thing to check is to make sure your arm on the walking foot is properly attached to the arm that raises the presser foot. Make sure your screws are tightened that hold it on (I wasn't tightening mine enough because I was afraid I'd break something) and finally make sure your needle is fully up into the needle holder and is also well tightened. If all the above is ok, then you might have a bad walking foot, but I noticed that if everything isn't installed and lined up properly the feed dogs and the mechanism on the foot that makes it "walk" won't move the fabric in sync and it will hop. Hope that helps you.