RE:SmellyRoller, I agree. Just like this was a coordinated when moving down this is a very healthy, coordinated move up. Add in future calls/puts, greenhill, ER, etc. this almost looks as much accumulation (by a PE or other party) pre-offer as it does a short covering (though we all know some of this is definitely happening.
i think we are still early for a BO offer but I suspect it is possible that someone is adding some prior to a bid.
time will tell.