Habitual Night Waking in 2 yo

Hi ladies

My DS is 22 months old and has been a reasonable sleeper until 4 months ago when he started waking everynight (and has done since) at 3 or 4 am. He seems happy as - I cna hear him talking away to his toys and singing. After about 45 mintues he often calls for me and I go in and give him a cuddle (in the cot), sometimes a nappy change, 1 or 2 songs and leave. He's happy with that - but will often take another 45 minutes to go to sleep. If I don't go in he can be awake for 1-2 hours! He's grumpy in the morning at 6.30 am when he wakes but then comes around and makes it to his nap at 12.30 or 1 pm. If we're in the pram/car he'll sometimes fall asleep earlier - so I know he's tired.

Here's what I've tried/thought of -

Hungry - doesn't make any difference if he's had a big or small dinner.
Nappy - tried changing it at 10 pm before I go to bed - no difference.
Not tired - settles well at 7 pm for bedtime and if he's had a short day sleep (30 mins -usually sleeps for 2 hours) still wakes up.
Cold - he has a superwarm sleeping bag and a heater - room is about 17 degrees.
Teeth -is getting canines but he doesn't seem in pain when he wakes up.
Changes in the house - none, except I'm pregnant. He's quite verbal/communicative so does know about the baby. He's started getting really clingy lately.

So, my question's are - anyone had the same? what did you do? was it just a phase?

He's such a good boy, but he's defintely tired. I think it's a habit.

Thanks in advance for your ideas/thoughts.

Edited by Buntingsmum

Thanks Danda. I've been telling myself 'it'll get better!'
I was going to call the sleepstore but I won't have to now! Thanks.

Sounds like I've got it easier than you ... I guess having two means they wake each other up? I hope your girls grow out of it soon.

My Mum reckons I should put him in a beed but I just figure he'll come and find me then!