I have a Gammill Classic Plus and find on an all batik I need to not have it so tight on the frame rollers--but not sure how that translates to a sit-down, maybe using your suspension system to relieve the weight of the quilt? I have had problems with Glide not staying in the intermediate tensioner--usually a sock over the cone does the trick, but sometimes have had to do another loop around the tensioner. Good luck--nothing mroe discouraging that having stitch issues! You didn't say, but do you have a stitch regulator? I'm having some issues with mine and need to re-set the regulator "wheel"--it only shows up when I'm working from the back and going fast in one direction--something in your explanation reminded me of this and thought maybe it's the stitch regulator that's out of whack.