Thanks for your prompt ideas! It is a good thing for me to think about other reasons for leveling off.

I am particularly interested in reading, so that has been the course of action I've been folowing partially b/c I feel so strongly against the strict adhearance to the basal that our district supports. I'd like to collect enough research to release my gifted child from "fidelity" to the basal. At this point they must read it (1-3 times), and do "skill" sheets, and take the tests, and then they can do some more work like read novels.
Pardon me...I just noticed I'm ranting.

I intuitively know that real books best meet the needs of high ability and gifted readers, I just need more data.