@Spatula: That's the point of this discussion. The CB is precisely correct there; that's the way the rules work. (Whether or not you would prefer them to is certainly a different matter.)
If you do house rule it, by the way, there's an easy way to do so (for arcane types only) in the CB: Click the yellow house icon in the bottom Feats panel to generate a User Choice feat, and then enter Arcane Implement Proficiency by selecting it or (if you don't have the Dex for it) entering Create Custom and just writing in the name of the feat - this is faster than listing all illegal options and hunting it down in my experience. Then give yourself AIP with the proper implement. This'll extend it to all your arcane powers, even ones gained through Dilettante.