I have a Baby Lock Quilter's Choice. Same thing happened to me early on but it was my fault. Good advice has been given in re to cutting the thread from the spool and pulling it out through the needle. I had left the presser foot in the down position and tried to pull my thread off from the spool. It then proceeded to wrap itself around the tension discs and "locked up". Fortunately mine was under warranty and they fixed it in an hour and cost me nothing but I learned a valuable lesson. As far as thread, I use every kind of thread with no problems. I do keep my bobbin area cleaned out.