Hello all, I have had this machine for years and love it, but it is pluckin my last nerve. Something has to be out of adjustment, as I sew the bobbin thread or bobbin area is jerking the top thread and balling up on the bottom of my material. I have noticed that it seems to work better if the thread tension is on 8 or 9. This seems to be pulling the bobin thread to the top so I tighten the bobbin tension. Then it starts again. Oh what an evil cycle. Help Pleassssssssssssssse. Thanks