I've recently been reading "Raising Gifted Kids"
http://www.amazon.com/Raising-Gifted-Kids-Everything-Exceptional/dp/0814473423which has some interesting insight into comunicating with your gifted kid.
Things I know that trigger avoidance or conversation dodging with my DS~7 are providing a solution when he just wants acknowledgement of his problem/emotion, probing into something he isn't ready to talk about, talking down to him or using "child-speak"/simple sentences (saw a bit of this from relatives over the holiday.)