All good thoughts. This has happened to me too. I have had it where I've adjusted the top tension all the way as far as it will go to the tight side and it not make any difference so what I did was get out my secondary bobbin case and after taking a picture of what it looked like when I started, I adjusted it by turning the screw maybe several times until the tension looked the way I wanted it to. I don't usually have to keep adjusting once I get this to my liking. It might be worth a try. My dealer can't figure it out either.