Hmm, it looks like my post earlier for some reason didn't show up until now (see 12:12)? Anyway, I'm LDS.
If you're taking him into the adult class, perhaps you could supplement church with playdates and other social activities with the other kids in his class? Then maybe he would be more amenable at a later date to going back to his Primary class. A couple of parents and I have had some luck with this when we had kids who really hated going to class. Does your ward do any kind of playgroup or kids' activities on a regular-ish basis? (My ward does, but in the US I think the number of kids in Primary tends to be much larger.) Have you talked to the parents of other kids in his class? What do they say?
If you can't work on it from the teacher's side, as I suggested in my other post -- and this should really be the thing to do; but I got the sense from your post that his teacher and the Primary presidency are all saying that there's nothing that can be done, and they aren't willing to call you to a calling that would let you be able to help? -- I wonder also if it's possible to work on coping mechanisms with him... if he gets bored, maybe he can make up his own story that illustrates the lesson. Or see how many scriptures he can think of in his head that fit the lesson. Or whatever. I mean, he might then get a reputation as the kid who is daydreaming, but that's better than the kid who is acting out
Does he behave in Primary proper? Does he like Singing Time or Sharing Time?
