Add me to the list! I was having all kinds of birds nests on the back of my embroidery. Took it to the dealer had it cleaned, same problems. Went back, first thing she looked at was my bobbin thread. Instead of using the best thin poly thread, I had somehow slipped in a bobbin from my Janome sewing machine with some crappy linty thread. That's all she had to do! Senior moment! I don't know how I did it, but I keep my embroidery supplies totally separate now from my sewing supplies!