OK, I just read your post and it sound very familiar. What kind of machine are you working on for this project? I have a Babylock Quilter's Pro and have run into this off and on. After speaking to friend regarding this situation, she said to me that often when you are FMQ your needle will glance off the edge of the face plate and make a little burr on the edge. Then when you go in that direction it will cut the top thread. I went back and looked really well and guess what? There was a burr. I took the faceplate off and use a tiny piece of "Mitchell's Abrasive Cord" and filed it off. I ordered it on line but later found it at my sewing repair shop. I also used a embry board to smooth the flat edge. I had replaced dozens of needles and thread pkus changed the tension with no avail until this suggestion. I never FMQ without this stuff on hand as I get in a hurry and pull or push the material. Thank you Jean for telling me this and making life better. JC