Help! 10mo DS awake for 3 hours in the middle of the night

[araminem]

We need help with our DS's sleep. We had a period (of some 10 days) where our DS slept through the night recently. However, before that and for the past 2 weeks or so, our DS wakes up at some point in the middle of the night and is awake for anywhere between 1.5-3 hrs (3hrs being yesterday).

So this is what happens:
We put DS to sleep sometime between 6:30-7:30pm. We give him milk, read a story, say good night and off he goes to sleep (mostly). But then when he wakes up in the middle of the night he ends up being half awake and half asleep. We have tried leaving him in his bed, and he cries. We have tried bringing him into our own bed (this is what we normally do), but he wiggles a lot and every so often cries. He is nearly asleep but not quite. If we put him back in his bed he will fall asleep but every minute or so he will sit up startled and if you are not there he cries.

We haven't tried any of these consistently as not sure which way to go. So any advice? Have any of you had this, and what worked? Help!