Have you taken a look more closely at the classes and courses you said he excels at? What is different in those vs. his school? Also what is the structure like at classes/camp vs. school? I was talking to one tester when we were struggling with one school and she was telling me that a certain subset of gifted learners actually can not learn, and truly suffer, in a more open environment like Montessori b/c without the structure they can't find their bearings of where to stop, focus, start learning etc. Just a thought, but sometimes you have to "flip" the problem to see what works and why, and then deconstruct what doesn't.