I know I haven't used one of these frames, but did you try adjusting the tension from the top AND the bobbin? I know people who have a separate bobbin casing (for those front loaders) for different types of purposes once they are adjusted which seems reasonable to me. Loopies always are indicators that either one of my tensions are off or the darn machine managed to somehow unthread somewhere while I was working on a project. It is never in a convenient place either.