Wyldcat: It seems to me that the observed disparity is between ability (the IQ score) and achievement (what he's able to do in school).
Ability is just one component of achievement, with some others being opportunity and interest. So if your child has had a multitude of good opportunities to use his abilities, and his interest has been engaged all along, then it would logically follow that he'd be achieving at a higher level than others within his ability range.
My DD7 is in the same IQ neighborhood as Wolf, and she faces challenges with the opportunities she's offered at school, which has in turn caused her interest to lag. Nevertheless, she spent last year doing mostly work that was two years beyond her grade level.
Now from what I understand this falls in the moderately gifted range and kids like these might benefit from some differentiated work or possibly a grade skip.
I don't think there's any "might" about it. You're still talking about being 2SDs above the mean, and qualified for Mensa. Keeping this kid at grade level is inappropriate.
