What is it about LO's this age? My DD is doing the same thing. She'd been taking two 30-minute naps and going to bed at 6:30 until just before Christmas, when the AM nap went to an hour 15 and no PM nap. We tried the tactic of waking her after first 40 then 30 minutes, and going down again 2.75-3 hours later, but it mangled everything. I hope it works for you.