We had a similar experience to what DeeDee suggests. Our daughter, who has PDD-NOS, was tested at age 4 (in the midst of intense ABA therapy) with the WPPSI-III. Her processing speed was her lowest score, she had some variations in sub-sets, and like your son, she was marked down for answers that didn't "check the box." This July, at almost age 6 -- and with three years of early intervention under her belt -- she was tested again using the SB-V. To quote Randy Jackson, "She slayed it!" Consistently stellar scores across the board. The head of G&T at her school said, "How wonderful to see the effects of quality early intervention."
When and if you do test again, I would highly recommend using a psychologist who has a rich experience base with Twice Exceptional children.
