Iceblossom

This would be the thing I would check. Even if your machine doesn't have much in the way to adjust the foot pressure, take off and replace to make sure the foot is seated correctly.

Watson

And the answer is........

There is something wrong with the bobbin case.

After checking everything else on the machine, I decided to switch out the bobbin case, as I have two for my Janome. One for regular sewing and one for free motion. I dropped in the one that is supposedly for free motion and it sews perfectly. There is a little bit of scuffing on the edge of the other one, but I can't imagine that would cause all the problems. I'm going to give it a good cleaning and put it back in after I finish what I'm working on.

Thanks for all the help, everyone.

Watson