help, please!

All right guys, here's what gives: we need some serious help. Some of you know we've been having some major problems with the transition to Kindergarten with our dear sweet 5 year old, Cameron. He's been in some pretty big trouble this year, some due to agressive behavior and some due to his immaturity. At first, I kinda laughed it off (after disciplining him) because it was kind of funny...mooning his class, peeing on the playground, etc. But by the third time the asst. principal called, it stopped being funny.

He has tried to choke someone in line.
He has stabbed a girl's hand with a pencil.
He has pulled down his pants 3 times.
He has hit, punched, etc etc.

This happens during recess, it happens during class, while in line, whatever.

Nine times, I think now. (If I wasn't so really frustrated and upset about this, I'd insert a Ferris Bueller joke here, but I really am serious) Nine times his behavior has been so bad it reached the Principal level. Nine times we've gotten a call. Nine times he's either had a referral or a suspension. This was a short week, what with fall break, so we had high hopes for a quiet week. Not so. He was in in-school suspension all day and will stay home Thursday and Friday due to once again dropping his drawers on the playground. The asst principal said the normal discipline for this repeated behavior would be a 3-5 day suspension, but that's a pretty long time for a kindergartner to miss school. Plus, I think after a certain amount of time, he wouldn't really get it...he wouldn't make the connection that 5 days was worse than 3 days or whatever.

We're pretty much at the point where we'll just admit defeat, say he's too immature to be in school, and try again next year. I really feel like we're trying everything! He's been spanked, grounded, lost fun things, lost recess. We've tried positive reinforcement, rewards, behavior charts. We've met directly with the principal. I've volunteered in his class. He's speaking with the school counselor. The principal has spoken with him. We have the pep talk each and every morning, but once he's out there, he just doesn't think. He doesn't think "oh, I should keep my pants on today so I can get a star on my chart." We've talked about changing teachers, but since he does it so often during recess, I don't think the teacher is the issue. I know that he definitely reacts with a couple of kids the wrong way, but he's not going to be able to completely avoid those kids, even if we do change classrooms.

And it's not like school is new to him...he was in preschool (a 'real' preschool with classrooms and buses, not someone's home) for 2 years and two months. His teachers said he was ready for kindergarten, that he understood the social rules and knew how to stand in line, raise his hand, sit when told, etc. I even called his old preschool teacher to see if she had any ideas. She suggested the fact that when he was in preschool, he didn't talk and thus didn't much get into confrontations. As his speech developed, she thinks maybe he's come into his own, so to speak, and can now stand up for himself. Or on the opposite side, perhaps he still struggles with communication in relation to other normal 5 year olds and when he can't get his point across acurately, that leads to aggression.

I'm OUT of ideas. I just don't know what to do anymore. I don't know of anyone else ever having such a problem with a kindergartner. It's frustrating and embarassing! I feel like this directly reflects on me as a parent. I need help, ideas, suggestions, anything. Or would the easiest thing be to just try again next year when he's 6?