I'm back smile I met with DS's teacher today and she was commenting on how he dreams the day away, but it's as if "his mind is going a mile a minute and class is too boring for him so he retreats to a more interesting world." She also said he "does better with more challenging work."

This last part is something I think ADHD and giftedness have in common - if the work is too easy the student will struggle to focus. This is something else that could be added to an IEP: "work that offers additional challenge" or something like that.