McSweeney, my daughter had a gap in VCI (142) vs PRI (121) too, though her biggest discrepancy was with WMI (116). I posted in these forums prior to receiving her full written report from the psychologist. Perhaps you might find some of the insight from aeh and polarbear helpful on that thread: http://giftedissues.davidsongifted.org/BB/ubbthreads.php/topics/229967/1.html

Are you awaiting your son's full written report still? I found that to be most helpful after testing, and only had a few additional questions for the psychologist then that she was happy to answer.