One reason why state tests and NAEP tell different stories

Actually, there are a lot of reasons...number one, they don't test the same things in the same way.

Eduwonkette has a good article on one of the other reasons: state accountability programs, all by themselves, improve test scores on state tests. That can be a good thing and a bad thing, all at once. (Yes, you need higher order thinking skills to deal with NCLB.) If you don't understand why it's both good and bad, see Jim Horn's piece (the link is in the article just below).