I will say that it is common for Handi Quilter instructors to tell you to loop the thread around the tension disks. I have a Avante (18" on a frame) and when I had problems with thinner thread, that's what they told me to do.
I also have the same issue with varying tension on the bobbin. Bobbin genies seem to help:
http://www.allbrands.com/products/53...-backlash-wash