I thought the same thing, but I came home and practiced without any spray basting and the machine sewed beautifully. I am not sure why it mattered, but with mine it did.

I agree, the BSR will run beautifully right up until you stitch onto an area with fusible or spray basting, and then it starts skipping stitches. Having had the BSR foot for my 440, 630, 730 and my 830, it's done the same on all of them. Different BSR foot by the way :)

I have had skipped stitches with my BSR and never knew the cause.
This is a revelation. I actually stopped using the BSR. I always spray baste so it very well may be my problem.
Thanks for the post.

You should still get the upgraded spring and washer as was recommended and is provided by Bernina.

The owner of the shop told me if I noticed anything else not sewing smoothly they would replace it. She said I am right on the edge of when they started making them with the upgraded spring and washer. I just got this machine in December. Hopefully it has the new one, but if not she told me they could do it in a day.

Sorry, but I find this doubtful. Mine was purchased in March(newer than yours) and my dealer has replaced about 50 of the springs and washers, mine included. My dealer has been great about it and has replaced them with a smile, problems during BSR or not. If I were you, I'd push for the replacement. You shouldn't have to argue to get a free retrofit from Bernina! Worst case, fib and say you're still having issues and want the new spring. Period.

I have had my BSR for about five years and use it alot. I have not heard about the upgrade, tell me about it please....

Technically, it's for the 820/830 machines, because the BSR runs at higher speeds, those who were having trouble with skipped stitches were offered the upgrade. But, I know some dealers are also doing them for the Artista/Aurora BSR feet as well. Same foot on all models.

They just replace the spring in it with a heavier duty one. It does help.

From what I understand they replace the washer too.

I can't get the repair person at my dealer to replace it. He says that's not the problem. I have a crack in my foot, which was not noticed until I picked it up from my last repair, and he insists I need to buy a new foot. I don't have a warranty because I bought the machine used. I don't like this guy, he treats me if I am stupid and don't know what I am talking about.
The man who owns the shop is nice, just the repair person who isn't!!!