Smelting Problems

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
After smelting, mainly netherrack, i thought i could get my product back
What actually happened was...:
Describe what happened here
The product, smeltee (the item I'm smelting) and the fuel were "locked" into furnace. I couldn't get them back at all.
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...It mainly happened when I tried to smelt a full stack of Netherrack with 44 coal as fuel.
3. ...