What thread are you using? Have you tried a different spool or cone of the same thread, in case the one you're using is faulty? Unless it is very old or poor quality I wouldn't blame the tension problems on the thread. I prefer to use poly threads (mostly tri-lobals but also finer threads like MicroQuilter and BottomLine) from MetroEmb, Connecting Threads, and Superior in my Innova. I have used cotton threads with no problem, but I don't like the lint the cotton threads produce. You do need to adjust tension when you're using a midarm or longarm.