Thanks, all. A few notes/answers:
1. Yes, his birthday is 9 days before the cutoff, and usually 4-6 days before the first day of school.
2. We had him evaluated by an OT in kindergarten, on a suggestion by his teacher, and they didn't find any problems/delays. It sounds like, however, the potential issues some of you have flagged wouldn't necessarily show up in an OT evaluation. We were already looking into getting him evaluated for his impulsivity, will add the handwriting problems to our list of concerns.
3. I definitely need to get the teachers' take on what they're seeing in the classroom before I start jumping to conclusions. From what I can see from home, they haven't done a whole lot of training in organization, but they may well be trying very hard and DS just isn't listening/absorbing the lessons. The note I received was to talk about DS's "work habits," but DS claims he just runs out of time to work on certain tasks.
4. There are two teachers involved here: math/science and ELA/Social Studies. The math teacher has an excellent reputation and I think she'd have been a great fit for my other kids. The ELA teacher I don't know as much about her teaching style. I knew her as an aquaintance/friend before she was hired by the school, and she has always struck me as being someone who likes things "just so" and is very, very concerned with details and appearances. That doesn't make her a bad teacher, but perhaps a bad fit for DS?
5. I don't think I'm ready to pull DS out of this school based on a few weeks of struggle. His first and second grade teachers were really great to him, and he made tremendous progress with them. The only options aside from this school would be a charter or a private; and frankly neither the charters nor the privates around here have better academic outcomes than our public school (except for the really exclusive, 30k a year privates, which, no.) I am willing (and eager) to work with the teachers and the administration to find strategies that everyone can live with, and am prepared to ask to place him in a different class if that becomes necessary. But pulling him out of school seems like a last resort, not a first option.
6. I wasn't aware that I could have him evaluated through the school, so thank you to all who mentioned it. I clearly have a lot to learn. :-)
DC1 -- 2005 DD -- 2009 DS -- 2011