i'm going to leave it on.  The two butts on top of it aren't close -- the bones don't budge.
I put a fork in the edge of the flat, and it twists a bit.  But closer to the center, it's much tougher.  
i don't get it.  All this time i was worried that the smoker temp was too low.  I assume that if the top rack is between 225-235, the bottom rack must be less?  (In fact, my bottom rack came off the little rack nubs, and it resting just above the water pan.  I would think that it's running closer to 212.