Door duplication glitch

Put the summary of the bug you're having here

What I expected to happen was...
For the game to give me only one door!
What actually happened was...:
The game gave me two doors to pick up!

Steps to Reproduce:
1. I went down to my mine, and placed a door!
2. I then knocked it down with my DIAMOND AXE!
3. It allowed me to pick up two WOODEN DOORS!
3. ...