It sounds like you fixed the problem. If you are ever looking for a great quilting machine, the 6600 Janome is the greatest for the price. Janome came out with the 7700 this year, but it is almost twice as much. The 6600 was designed for quilting.
Auto Thread cutter is a God send when piecing. It has a separate motor for winding bobbins and decorative stitches. I also puchased a Janome 3160 for class....only 11lbs. with the autho thread cutter, start stop like the 6600. Seems like all we do in quilt classes is piecing so that little machine is great. If you are interested, PM me and I will tell you the best place to purchase. Diana in TX