Why won't you sleep?

We are having some very long nights in this house. At 5 months old Nash decided he loved to sleep, and from then on he did not wake us up one single night. Until a few months ago. I can't remember exactly when it started, but for the last few months Nash is out of bed multiple times a night. The first time is around 1:30. He very quietly opens our door and doesn't say a word, but stands there until I get up and bring him back to bed. I hear him opening the door and sniffling a little, or whatever, and I don't talk to him because I don't want his "visits" to be "social". I just bring him back to his room and silently tuck him in and leave. And that's fine. But then he gets up again, and that's when the trouble usually starts. It could be as early as 4:45. And he comes into our room and when I get up to put him back again he protests. Either starting to cry or throwing himself on the floor. It gets hard then, because even if he's back in bed sometimes he'll kick off his blanket, and he won't go to sleep unless he's tucked in by mommy or daddy. My goal, of course, is to get him settled as quickly as possible so I can go back to sleep! Sometimes I can get him back in bed without much trouble, but then sometimes he's up again and in our room 10 minutes later, just as I've fallen back asleep. And this can go on and on. Of course we're worried, also, that his screeching and thumping protests will wake up Margot. I can't say that I've heard her wake up because of him, but she does seem pretty tired some mornings and I wonder if she's been up because of him too. 6:00 is really the time we've deemed OK for Nash to be out of his room. Before then, I am just pretty tired. I always start out patient, but that's hard to continue on those mornings I've been up 7 times with him in a night, and basically haven't slept since 4:45AM. Ray helps by either bringing him back sometimes or letting me sleep in on the weekends when it's been a bad night. But I am first to hear Nash when he comes in our room, and sometimes he says he wants his Mommy, so Ray is really getting up for no reason.
I probably didn't write about this sooner because it didn't really bother me for a long time. I guess I should have tried to fix it earlier, but I thought it was just a little phase he'd grow out of, and he was peacefully going back to sleep. But it's getting worse now and he is in school now and I don't want him to be tired. So time to try and get the kid back into a good sleep habit.
The first book I read about sleep trouble in 3 year olds suggested something that seems obvious that I hadn't thought of. Bribery. Why not? For the last 4 nights before Nash goes to sleep we tell him he needs to stay in bed all night until morning and not come and check on Mommy and Daddy because we're asleep. We're in our room and he's nice and safe and we'll see him in the morning, after a good night sleep, when it's light outside. AND if he sleeps all night long we'll be so proud of him! And he can have chicken nuggets from McDonalds. He seemed to understand and be very very excited. But it didn't work. So we've upped the ante and gotten him a huge awesome garbage truck he picked out. In NO WAY does this kid need another truck, but I'd buy him just about anything get my uninterrupted sleep back. And along with the truck we bought him a clock. Last night before bed we had lengthy discussions about what was to happen last night. And there was illustrations.
This did not work perfectly, but I think we're heading in the right direction! Nash slept until 4:45 this morning! And then when I tucked him back in he did not protest, and he went back to sleep until 5:50! At that point I didn't want to worry about those 10 little minutes. BUT, with all the emphasis we put on the 6 I am definitely disappointed that that little guy wasn't on the clock when he got out of bed after all. So send me happy thoughts of Nash (and myself) sleeping peacefully! And also send me any suggestions you've got!!
Though this is totally unrelated, we've done some work on Nash's room. He wants his walls orange. So far there's only one orange wall, but it's really cute.
And Ray made these totally awesome cubbies for him out of these heavy cardboard and wax tubes from Lowe's. Aren't they cool?
XXX