A couple thoughts:
How's his sleep before he wakes for the day, say from 5AM on? Is he waking around 4-5AM? If so, can you get him back down w/pacifier so he doesn't get into the habit of waking then? Failing that, how about wake-to-sleep - just go in and get him to stir ever so slightly, sometimes re-sets the sleep cycle so they sleep through a habitual waking. (Wish I'd known about this when Josie was 3 months!)
My other thought, if Josie's case history at the top of the Naps board isn't giving you any more help, odd as it sounds: let it go for a few days and then come back to it fresh. I gotta tell you, with number two here now, I've had to be a lot more relaxed about short naps, or number one child would never see me 'cause I'd always be in Nat's bedroom trying desperately to get her off to sleep again. Sometimes it works, sometimes not, but if not, well, we try again in a while.
When Josie was taking 4-6 45-minute naps a day, I looked at it as lots of breaks for me; I almost missed it when she went to "only" 3 naps, cause even though they were longer, I had longer to wait till my next chance to catch my breath! LOL
Meanwhile, if you haven't caught the Announcement about Josie and her short naps further up, check it out. She's almost 4 now, but some of the memories are far too clear! LOL :?