Report "I have sailrite ultrafeed and the thread keeps knotting up underneath the canvas I am sewing on.....help? I have pulled the bobbin case out and cleaned it, but before I started to adjust the timing, I thought I'd see if there might be something silly I'm not thinking of...Worked fine last year when I last used it. Also, it was on my boat which just had a very very rough ride coming home - WA to CA"