When I pull my bobbin thread up through to begin quilting my bobbin thread will break. I have to take it out, pull enough length out to be able to pull it back up through the quilt again. This happens about 50% of the time and when doing a continuous design it doesn't happen often only when you're doing designs that require a lot of stopping and starting. I'm being very smooth with my take off, I'm not jerking the machine. Any suggestions?