This happened to me many years ago...the math just didn't match what the pattern said.It was more than just a little bit that needed to be eased in, and I thought that it just couldn't be right, so I added up all the measurements...and the pattern was wrong. It was a very popular designer. I wrote to her, and she agreed with me, that the math was wrong and how sorry she was, and sent me some free patterns and thanked me for letting her know.