Trap doors can not be placed side by side

Put the summary of the bug you're having here

What I expected to happen was...:
placing trap doors next to each other

What actually happened was...:
if a trap door is put on either side, above or below an existing trap door they both pop off. Diagonals work fine.

Steps to Reproduce:
1. place a trap door
2. place a second trap door on either side, above or below the first trap door
3. they will break

ect. trap doors placed next to each other that are carried over from a previous version will break when 14w25a is activated on a world.