Are you positive the eggs are fertile? Also you could be keeping them to moist, but I wouldn't switch them to dry vermiculite or change the temps. You want the temps to be as constant as possible. If they look bad with mold throw them away or atleast put them in a seperate container, you dont want them to get the other eggs moldy. Also make sure to open them up every now and then. I put a tiny hole in the side of the container so the air doesnt get to stail, but not one big enough to let to much humidity out.