My dd is 6 months old and has always had trouble going to sleep. She has this weird thing going on where she becomes sleepy, with droopy eyes etc, then starts shouting and crying, then goes back to being sleepy, so that you think she's finally going to go to sleep, and then starts shouting and crying again! What's that all about? Is it to do with fear i.e. could she be frightened about going to sleep? Or is she frustrated when she's tired and doesn't fall asleep immediately? Any advice?