First of all, good for your son for trying to stimulate his mind and working ahead.
I missed how old he is (?), but I do have a few thoughts.
First, clearly there is no call for punishment of any sort. I'm also guessing from your post that the teacher isn't even recommending punishment. When you say that he's "in trouble" for working ahead, and that she is suggesting that only children who can work ahead without major errors do so, I'm not picturing her as being harsh here. I can picture her being perfectly reasonable. I doubt that she is putting him "in trouble" by offering detention or any other punishment, right?
He's 7 and he is old for his grade (1st)(which is something our district REALLY pushes so that is not really my doing as much as it is the schools; however, he also has a LD in writing so we're in a weird spot). And, they *are* disciplining him for it - they pull his ticket (the class system is such that the kids get "caught-being-good-tickets' but you can't get a 'caught-being-good-ticket' if your 'ticket' is "pulled" for an infraction, then the next step are numbers on your conduct chart, notes home etc. I do, however, get the feeling that she wants me to do some sort of discipline on my end to support her in disciplining him for this because she is sending notes home about it... However, she does NOT have a harsh demeanor and she is generally flexible, etc. So, I definitely think that once she realizes this is behavior that she is going to have to accomodate somehow, she will do so.
