hi there i am having very similar probs with my nine year olg daughter. lack of confidence at school resulting in bad behaviour at home,its so soul destroying and difficult esp when out attention seeking and cheek. thing is my daughter is lovely smart and very bright im so concerned as i feel things can only get worse,just remember to keep your cool and no matter what praise him as often as poss letting him no that he is a very important person if the school wont help try another proffesional body good luck.

Lou, please, please talk to the school. It is obviously very upsetting, but the school MUST have a anti-bullying policy and they should be able to help your son learn to make friends, or at least help this process.
I'm presuming you've tried inviting other boys over to play... mind you, if he's finding it hard to socialise, it might be better to take him and another boy somewhere really fun, where they won't feel awkward not having much to say to each other. They'll just both have had a good time together. That's a good start. If he does have another child round, maybe you should stay with them and help them play ....

Good luck. You could also try speaking to him about how to make friends, what to do and what not to do. I have a 9 year old girl, and I do try to make her to begin to try to see things from another child's perspective ( eg 'You can't expect to always play the game you want to play.... sometimes you have to play what another child wants to do.....etc')
Please go into school. Your son's social development is a responsibility of the school and he has the right to not being bullied and the teachers have to ensure this happens.