Firstly she sounds very immature. I can't count on my hands the times DS has not completed tasks in the times given.

I hate teachers that send home notes like this. And don't get me started on the language "Dissapointed". I'm sorry but whoopdeedoo. That doesn't help you or her or DS. Maybe trying to sit down and figure out what the problem is might help. Children aren't obnoxious just because. Even if it looks that way I can almost 100% guarantee its not the case. I'm not obnoxious just because. So why not sit down and work out what the problem is. I don't think you are overreacting. I think you are on the money. Is there a way you can assure he won't have her next year? I can't believe how little support they are giving you and him. It's disgraceful.