I think this problem is related to the new social -> military game mechanics. That is, when you're not building anything in social, the game with think you don't have any social spending (since it is being diverted to military). So when you add the building, the number listed isn't correct (they need to update their numbers). However, if you just add another building, or exit the planet and reenter, or switch planet and switch back, the number should be displayed correctly. It is just a display error, nothing to worry about it.
