I can offer you my sympathy, I have an 8 year old DS who can also be a handful. Some of the behaviour you have mentioned sounds familiar, particularly the dinner issues and the yelling back at you when you tell him off. Firstly, I would not tolerate physical violence from my DS AT ALL. He went through a stage at about the same age as your DS when he would hit or kick if he was annoyed and we punished immediately by sending him to his room and removing a special toy or privilege for at least 24 hours. You absolutely must follow through with any punishment. He was not allowed to come out of his room for a set time (usually about 15 minutes) BUT that time did not start until he was sitting quietly 'thinking about his actions' - not sure how effective the thinking bit is, but it sounds good! If he was rude, yelled at me, stepped outside his room... then the time he had to sit quietly was extended by 5 minutes. After he had sat quietly and calmed down, either DH or I would go into the room to talk to him about what he had done and he would generally apologise himself, but would be asked to apologise to whomever he had been nasty to if he didn't do it himself. Maybe the bedroom won't work for you, but it worked for us. The trick is to be very calm yourself throughout, as I found that the angrier I got, the angrier my DS became!

On an average day, I find that my DS behaves best if i can engage him in an activity. He loves to be outside, so I get him doing jobs outside to help. He likes to be physically active, so something like cleaning windows or scrubbing the verandah is good. I encourage him with positive reinforcement - 'great job, mate, I love it when you're helpful. The windows look really clean.' His chest swells up and it seems to spur him on to do an even better job. My boy is a handful when he is not busy doing something! By the evening, if he has had a busy day, he is tired and happy to have some down time. His happiest downtime is something which involves the rest of the family, such as a card game or even just sitting around the table having a chat - something that engages his brain.

My DS is a great kid, as I'm sure yours is! My boy has always been well behaved at school and like your DS's teachers, ours were shocked to hear that he could be such a bugger at home. I'll be honest and say that there are still times, such as if we are going out for a meal or we have a doctor's appointment or similar, when I think 'Good grief, please can the kid behave!!', but he is certainly a lot better than a few years ago. It just takes time - and the patience of a saint!! Good luck!