If you hold down the 1 or 2 when selecting your BSR mode it will turn on the warning beep that lets you know when you're moving the quilt too quickly for it to keep up. I found out that I had to slow down a bit!
I also have the Bernina 440 with BSR, and I can say it works best when I move the quilt at a steady speed. Like Goldilocks: not too slow, not too fast! Charity quilts make good practice pieces.
