Naruto Shippuden Ultimate Ninja Storm 2 achievement help?

One of the achievements on my game didn't pop up and I know I did it right. When you finish all the stuff with sending and receiving letters with the messenger birds your supposed to get an achievement for completing all correspondence events. I did that and later after doing everything else I got an achievement for completing all of the events in the game but I still haven't got the achievement for the correspondence events. Does anyone have this game who can help me?