Masteries selection problem

Whenever you're waiting for a match, go and check masteries page of any other summoner's profile. Once you're there, keep waiting until a match is found. Now that you're in champion select, you'll see the other summoner's mastery pages as options to choose for you're upcoming match. You won't be able to actually select their masteries, but is a bit annoying, because you can't choose your own either.