Gayle is right, there was an issue identified with the spring, your Bernina dealer should be able to fix that, and, make sure your BSR has been updated, dealer should be able to do that also. This may help. Make sure you have the correct needle and thread. I can't think of any other tips right now. Did you just get this? If so take the foot and maybe your machine back to the dealer and use it while you are there so they can see what it does. Good luck.