I cannot tell you how many times I've seen people post and ask about "AP bug" just to be told over and over that they've reached a cap and none of them bother googling what they think is a ''bug " themselves before posting.
It's about time you just put a message under the achievement number.
(Daily 15.000 cap achieved: you will no longer get AP from dailies)
Edit: I KNOW this was said before, so no need to tell me. It's just that Anet doesn't seem to care to finally add a simple line.