I am currently unable to produce Smooth Stone blocks using the furnace. I can place Cobblestone blocks in the furnace with a fuel source and the furnace will produce Stone Blocks. Then i can add the Stone blocks and a fuel source to the furnace, but this does not produce Smooth Stone blocks. 

When Stone blocks and a fuel source are in the furnace, nothing happens. There is no animations in the furnace screen and no animations on the furnace in the world view. This was working at least a couple weeks ago, but now it is not.