Put the summary of the bug you're having here

What I expected to happen was...:
That I could put in and take out items like an ore to cook or coal to fuel....

What actually happened was...:
When I put my porkchop in, I couldn't take it out. I couldn't even put in a coal to fuel the furnace either.

Steps to Reproduce:
1. Insert item into top or bottom section
2. Attempt to take either items in or out
3. Find out that anything you put in the top section won't come out, and nothing will go into the bottom section, making the furnace useless until a bugfix is applied.