Hi,
Long NWs are hard, but we had them too around the same age. It could either mean UT if they are up and chatty/happy or teething. I'm no expert, but I'm willing to share my experiences with you and some things I did to help.
Have you read these links?
http://babywhispererforums.com/index.php?topic=95670.0http://babywhispererforums.com/index.php?topic=163278.0You might be starting the dreaded 2-1 trans. It's a long process though and I think your lo is still too young to be dropping that last nap. In fact, looking at your EASY (which is very similar to ours and my DS is 14mo) you might think about adding in more A time and that might help.
Is there a reason why your second A time is only 2hrs45min? After a 1.5hr nap I would think your DS could handle 3hrs if not 3:15?? Does your DS fight you on that second nap? Does he wake naturally after 45min or do you wake him? Is there any BT resistence? Is he STTN?
If you push that second nap later, say 3pm your BT would be later and that might just help with the long NWs. If after tweaking your EASY a tad and things don't change, then it could be the teething monster and unfortunately you will just have to ride it out.
Hang in there.