Stone slabs on top of the blacksmiths shop's are floating one slab above the roof.

Put the summary of the bug you're having here

What I expected to happen was...: the stone slabs in a NPC village blacksmith shop to be sitting right on top of the roof.

What actually happened was...: the stone slab was floating one slab above the roof of the building

Steps to Reproduce:
1. load Minecraft 14w27b
2. go to a NPC village
3. note the floating stone slabs