@ liza: My daughter started having night terrors 2 months ago (she was 27 months old then) and she would wake up screaming 30 minutes after falling asleep, during naptime and at night. Nothing would console her, not even nursing. This went on for about 2 weeks and just disappeared on its own. We never did figure out what triggered them (she was not teething or sick, we did not have any changes in our routine, etc) and we also never knew what we did to make them go away. We did notice that the episodes went on longer if we tried to rouse her and she would wake up scared and confused. If we just let it run its course, she would quiet down sooner and would fall right back to sleep. When I ask her about it in the morning, she says she does not remember being scared and that she did not have a bad dream. We did notice that it tended to occur when she is more tired or when she went to bed later than usual. Maybe just make sure your dd is not overtired? Sorry I cannot be more helpful than that - just wanted to let you know that this, too, shall pass.
@ reei: Funny, my mom and grandma used to say that to us all the time when we were playing too boisterously! I think it is an old Chinese superstition...hahaha!