No more than 4 hrs of sleep Sleep problems....

I have an 8 & 1/2 month old daughter. She is pretty good with naps, but sucks at night time sleep (no pun intended!) She has 2 naps per day, one from 9ish to 10 - 10:30ish, and an afternoon nap from 1 to anywhere from 2 to 3ish.

Here's the problem: nighttime sleep. She's in bed by 8 and awake by 11 or 12midnite. We're trying a modified cry it out sorta situation, and she's usually up, screaming for about an hour. We sort of pop in to reassure her, but no feeds at that time. (I'm nursing) Then she's usually up by 4:30 or 5, raring to go. Not crying this time, but awake & happy, babbling/playing. She's in her own room.

Any thoughts/advice? All welcome.