What to do with Dealers that don't enforce rules?

[Arito]

skin city how old are you, seriously?

As for the topic. I let it depend on the juicyness of the game. If I think my being a nit will somehow stop the game from being good I will not pursue the issue further. It is a rule, and it could be seen as unfair to any player at any time (the person holding AA in the example), but as was correctly mentioned, you are just as likely to be the person with 99.

Generally, the games described in the OP are very good so I will let it slide after commenting politely on it once.