CO is Coding (not Comprehension), right? If so, my DS8 has a
very similar score profile to your kid (though, like ElizabethN, on the WISC-IV). He is very slow but neat when he writes, and he has trouble keeping up with his classmates. He's fortunate to have teachers that understand that, if he's given more time, he can produce some pretty amazing stuff.
I've wondered off and on if he is dysgraphic, but I've never considered CAPD. Are there specific reasons you think that this score discrepancy would point towards that, or are there other aspects about your kid's personality that lead you to believe that?
I found this link to be pretty helpful:
http://bitsofwisdomforall.com/the-frustrated-learner/
