Originally Posted by
Vistacruise
..........When I started really paying attention, I realized that it was doing it after I would finish a row, move the quilt, and put the foot back down. ..........
With what you have said, my first thought would be, by chance are you catching it as you shift your quilt around at the end of the row? I never had that problem with my 6600, but have done that on a different machine.
Otherwise, my thoughts would be to phone your serviceman and ask his advice. It may be just a minor adjustment that you could do, or a quick-fix at his shop.