I have had similar issues with my Bernina 830 but my dealer is fantastic to work with. He has even offered me a limited 830 for $1900 plus trade in my old one. It's behaved fairly well as of late but just two weeks ago I was FMQ and I had the same problems you described. The only thing different I did was change color of thread but same brand and it had fits!!...I plan to quilt again next week so I'll give it another chance!!!