That's an interesting one. Perhaps try setting your filling by chilling it after putting it in and putting the top layer on, but before trying to DO a crumb coat or icing it.
Also, make sure you level the bottom layer, because the one I didn't level split in half about a half hour after finishing the basketweave. The icing was too heavy on the sides and pulled it apart because I was counting on the filling to hold it up since I thought it was nearly level. That post and photos are in Cake Disasters Forum called "Earthquake Cake".