That was an interesting thread...thanks! Well, the time I put him down doesn't seem to make much difference, but what I've decided to try (to test if it's a new habit forming or just a developmental leap) is to basically make him stay in his room until he can lay there still & quiet for a substantial amount of time (which, so far, he can't do without actually falling asleep). So I go in after about an hour of play and tell him he can come out when I've heard him lay there real still & quiet for a while. He then continues to play for another hour (sometimes 2!), but after a few more visits and reminders, he finally gives in and lays quiet (then, of course, falls asleep). Today I put him down at 1pm and he finally conked out at about 4:15. Is that mean? My husband thinks it's not good, but it doesn't seem to affect him - he still goes down to bed just fine and sleeps 11-12 hours at night. And he isn't terribly unhappy to be in his room. He goes in there for a nap just fine (probably because he thinks it's his best play time!). Anyway, I decided to try it for at least 5 days and see if it's habit. After that I'll change my approach to quiet time if he's still doing the same thing.
Thanks for all your input! -Angie