Just wondering how long have you had your Bernina. The skipping stitches seems to be a common complaint. Personally, mine never actually skipped stitches, just occasionally had one bigger then the others. This was usually when I had made a quick or jerky curve or turn. There is an upgrade that involves replacing the original spring with a stronger one. I just got my machine in April, but had an issue with the threading path, when I took that in to get it taken care of, I took the BSR and asked if it already had the new spring since it was new. They said no, but they replaced it at that time. I have used the BSR a few times since then. I still get an occasional longer stitch, but I can live with that, it is certainly an improvement to what I can do without it. What I don't get is an actual skipped stitch where there is a needle hole where the needle went down but did not form the stitch.
I would recommend that you give your dealer a call asap. No reason to stress over it when the machine has a warranty and it is an issue that they should address to your satisfaction. I guess I am spoiled, my dealer is like family and works until any issue I have ever had with any of my Berninas is resolved.
Good luck.