I realized that Paper Scaling was checked. Once I unchecked it, they printed fine.
The problem was, since the first rows of labels fit fine, even when they are printing wrong, I didn't notice the problem until I had many pages printed and was getting down to the middle of the pages.
Oh well, I use the top rows the usual way and have to cut the bottom ones out with scissors and tape them down with clear packing tape. So, I haven't thrown any out, I do use them, but it's a pain and not as convenient.