Sounds a bit like my DS! As soon as we hit the bedroom its partytime! I've given up on the set bedtime thing. Instead he goes down about 4 hours after his afternoon nap (if its a good one of say 1.5 hours) or 3 hours after if its a short one, i.e 30 minutes and that works so much better! I tend to cave if its too much of a battle and let him get up for a little longer and try again 10 - 15 minutes later and this has almost never backfired on us!