Not surprised about the Sulky. Here's proof: take a small length of another polyester thread. Pull both ends. Tough to break? Now do it with the Sulky. Breaks way too easily! I had the same problem with the thread getting caught up in the auto threader. The Sulky was also terrible with my embroidery machine. I now only use strong polyester threads, and very rarely will I use cotton. That is kept mainly for potholders. Use a long narrow nosed tweezer to clean out the blade area of the automatic threader. Threads and lint catch up in there fairly quickly.