Glenrose ... are you talking about the in-game leaderboards or the stupid Elite by Beachbums method of tracking your stuff?
Elite is worthless when it comes to tracking stuff. I've contacted them several times about stats and challenges for both MW3 and BO2.
Well, the problem with that suggestion is that in MW3 I am at 10th prestige and have been for more than six months. There is nothing else to unlock!
I'm having a very similar problem with BO2. For certain challenges, there is nothing else to unlock.
BTW ... how do you clear your console cache???