How married are you to staying at this school? I have one gifted child with inattentive type ADD and one gifted child without. Even the one who does not have ADD didn't perform as well when she was placed well below her ability level. I'd wonder whether boredom might play into this as well and I might seriously consider interviewing other schools to see if you can find one that will consider placing him according to his ability and accommodating any weaknesses that may exist rather than focusing so much on current achievement.
Also, what did his IQ scores look like overall? Both of my kids have some serious variance within the subtests but my ADD kiddo had a major discrepency btwn speed and working memory vs. perceptual reasoning and verbal. I understand that is not uncommon among kids with ADD.
