Ok here's my duh moment. I had just received my new Janome 6500 a few years ago and was so excited. Had it all threaded and ready to go to a class that weekend. During the class, I ran out of bobbin thread so my friend let me have one of hers so I wouldn't have to stop and wind a bobbin. Well my machine would not work right after that! Tried rethreading, thread kept breaking. Even called my dealer and he walked me through everything he could think of over the phone. I finally just had to sit there while the class continued. The frustration factor was off the scale. I took the machine to the dealer (a 200 mile one way trip) and it turned out to be the bobbin. My friend was using a Brother and apparently Janomes and Brothers do not like to swap bobbins! Talk about feeling stupid!