My lo does better in the dark, too - when it's light, she gets distracted by all the stuff she can see. I think therein lies the problem. When sleeping at my mom's, since the room doesn't really get dark (I do put stuff over the windows), it helps a little to drape blankets on the sides of the crib so she can't peek through the rails. Another major problem though is that she's used to quiet, and my mom's place is anything but! The TV is on over there, and the walls are thin. So, I always turn the little fan on in the guest room to drown out all the other noises. It also helps to have the blanky she always sleeps with at home.