10 yr old has anxiety about bedtime

My 10 year old son tells me he is afraid to go to sleep. He says he is afraid of having a bad dream. He has had nightmares before, but they do not happen all the time. I have tried to talk to him and get him to feel that he can have some control over his dreams or at least his responses to him, but it doesn't seem to help much. He postpones going to sleep as long as he can, often lying in bed talking or singing to himself after I have left the room. I hear him sometimes 45 minutes after I've put him to bed. I've asked him about it and he says he's just talking to himself (as opposed to an imagined being), and I think he just does it to avoid going to sleep. How can I get him to be more relaxed about falling asleep?

[margypops]

Does he watch anything scary on TV or any PC games, could there be any outside reason, I think if you dont make an issue about it it will quietly solve itself, let him read in bed for a while as that is a help, what time does he go to bed, is he tired enough. Does he regularly play some sports, outside activities Dad take him out and do guy things with him.