Oh dear ... I can't believe after that drive it worked perfectly for them . Sounds like something that would happen to me. I use the bernina 440QE occationally on my grace frame and changing the bobbin is a pill. But, I wind tons of bobbins before I begin, so that helps a lot.

By the way, I fried my brains with the manual with I first got it. It does help, but I have to refer back to it when I do something I haven't done in a while. I would say, keep it handy.