Naps are all messed up - how to fix?

[BertieBotts]

DS is 19 months. At 14 months he dropped to one long nap in the day, in the morning at about 11 for 2-3 hours. This was working fine and his sleep at night was fine etc.

Anyway recently, he has not been going to sleep for his morning nap. We go to toddler groups in the morning and it was usually on the way home that he would fall asleep in the buggy. I have been trying walking for longer, going round the block a few times, reclining the buggy, but he has just stopped falling asleep like this.

This would be fine (although the thought of losing his nap this early is a bit scary!) but he tends to get tired then in the afternoons. I can't get him to nap straight after lunch and any later and he won't go to bed. Sometimes he stays up and it's fine and he goes to bed at 6ish happily, sometimes he stays up and is ratty and then too tired to eat his tea, but goes to bed ok, and if I go and do anything in the afternoon and he is in the carseat or buggy then he just falls asleep, and is impossible to wake up. If I pick him up he just falls straight back to sleep in my arms! So he ends up sleeping for about 2 hours and then doesn't want to go to bed.

Any advice? I don't really know what to do! I don't want to do any kind of controlled crying etc (and besides, he sleeps in a bed).

[StayGoStayGo]

DS is similar, now at 20 m I have to wake him up after 30 mins or so (depending on time of day) or just let it be. If he has been up all day I will do dinner about 4pm before he is too tired to eat, then just try and keep him up afterwards. With DS1 I more or less let him sort himself out and went with the flow and just gently encouraged him into a routine. I now have 2 boys (4 and 20m) who usually go to bed together at 7pm very happily Some days they fall asleep in the car etc., but there's not alot I can do without poking them all the time or something.