Scores not recorded when you re-play and beat expert's time!

I finished the game, all with gold, and the nutcase that I am went back to beat the expert scores that I didn't beat in the first go-around. I did beat several of them, but when I went back in to play again the scores still gave the "best score time" to the same expert score it was before. I know that's not a big deal, but why put a message at the end of the game that says you can go back and replay levels for better scores?????? A bit frustrating!