I am not sure what to tell you to do, but I know someone will have some tricks for you.
With regards to my experience - my son goes through phases of this. I don't really change too many things except his naps - I mean I am not going to put him down for his first nap at 8 am - so in that sense I change - the earliest I will nap him is 9 ( but he is older) and also I don't take him out of the crib before 630. Unless he is screaming which he usually isn't. And I totally agree with Marissa's Mom - my son would regularly fall back to sleep when he was this age. I treated anything before 630 like a nighttime wake up.
You might want to make sure he has a full belly before bed, too. Sometimes that does make a difference with my lo. Like if he only has a piece of fish, broccoli and peaches for dinner he might wake earlier b/c he is hungry. But if he has a nice fatty/starchy meal like chicken, beans, and rice he'll sleep later.
Anyway, just a few thoughts.