Well Travelocity probably agrees to book out a certain number of rooms so they get a deal.
I know you can get rooms cheaper sometime on Expedia for Disney hotels than booking with Disney. It is not uncommon.
Also you don't get any Loews benefits when you book with Travelocity. So if you have status with Loews it is not going to get you anything.
I have also heard people complain that Loews in general puts people who book with sites like Priceline in the worst rooms. Maybe someone who has first hand experience can comment on that, but that does seem resonable to me.
BTW: Did you check promotional prices and AAA prices?