things are going so well. I think if it was me I would be having a meeting with the teacher and aid. I'm sure this isn't the way anyone wants the school year to start. It might be helpful if you go in and observe how the day goes and show them what you do (I don't think it could hurt). I would almost think the aid would welcome some suggestions if it would make her job a bit more enjoyable.
Maybe they should let him hang in the sunroom to see how fun it is so that way he knows if he is being good he can go in there! I don't have alot of suggestions hopefully things will start to get a bit better!