I have the 430 and I just needed to slow down. My first try, soooooo many skipped stitches. After I slowed down, a lot fewer. My machine will work for 3/4 of the quilt perfectly and then it will start skipping stitches for about 5 minutes. I stop, give the machine a few minutes break, and then it's fine. Weird, but probably good to remind me to take a break :)