Jben, you've got an established colony don't wreck it lol. Lots and lots of people have problems with there first litters. Search it on the forums.
If I were u I'd count my losses with this first litter and let em have another. Keep your 1.3 in the tub and let them try again.
If you split em chances are you'll have to reestablish the colony and that could take a while.
Sounds like your doing everything right. And sometimes the babies won't move, maybe there not dead. I'd just leave em be for a day or two only bug em for food and water.
Good luck!!! Jeremy.