I've had the 7100 for several years. Some days I love it..some days I want to stomp it, lol! I have those same problems and I keep practicing w/ diff thread until the problem goes away. One thing I have done ( besides loosening tension) is to wrap the thread on the 'thingy' only once...almost on day one! I find more success with king tut poly thread and sz 14 needle. Hope you figure it out. It's a lot of fun when it's working right.