thanks for all your replies. Our main problem with him is that he is either an absolute angel (over the top really, and generally when he wants something), or just being bloody awkward to cause maximum problems for the rest of us (he is 2nd of 4 children) - refusing to do as hes asked - i.e. shower, tidy table, annoying the others, getting in 'their face' all the time, sulking big time,.....you get the idea. We did used to have (up until a few months back) big tantrums, "i hate you" kind of thing, but that has been replaced by big sulks.
I know it is our fault - we have been very inconsistent with punishments with him, and often me and hubby dont 'stand united' in his discipline. We've flitted from taking things away, putting him in his room, going to bed early, and often go back on what we have said. (Gosh, now I'm typing this out and actually admitting it, we really have asked for these problems!) I think having 4 kids (dd12, ds10, ds4, dd1) its all too easy not to follow up on punishments. However its really getting to the point where his behaviour at home is causing big problems. At school he has always been very well behaved, so I know he is making the choice to behave like this. He only has a DS (no wii, phone etc), and as we live in rural france, he doesnt often go out and about with friends.
Sorry for the long post, just got to get it off my chest. Thanks for listening.