My 10 month old DS2 has been sleeping reliably through the night fr about the last 4 or 5 months, however the last 3 nights he has suddenly started waking 3 and 4 imes in the night, but will go straight back off if I go in and put his dummy back in. He seems generally unsettled in his sleep and is crying out a few times in the night, but when I go and check on him he seems to be sound asleep. He already has 6 teeth and teething in the past hasn't disrupted his sleep like this. However he is cruising and getting really frustrated as he can't walk alone - could this be it. Any ideas, or has anyone else experienced this???