Before updating, I had a fireplace that kept in a burning block of Netherrack, made of bricks and cobblestone, which ensured it did not spread to my wooden floor. Since the update though, the fire now spreads to the brick floor, burning it, then spreading to the wood. I've researched Minecraft fire and its qualities and burning range, and it does not comply. And to make it clear, this is occurring in Version 0.7.3. I listed this bug as 0.7.2 due to the system telling me it did not exist.