I would try going back to 2 naps for a bit. Exactly the same thing happened to me last month with DS (he is 17m). Since he went back to 2 naps he is much happier and sleeps longer (3 hrs with 2 naps vs 1 hr with 1 nap!). I would just give it a try and then try the one nap again later. I heard it can take some time for them to fully transition and that some days are 2 nap days and some are 1 nap days. Good luck!
Mama to my wonderful little DS April 5th, 2011
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