What I expected to happen was...:
The wood should have burn just like overworld planks and logs should. It should also be able to be lit on the side 

What actually happened was...:
I could not light it with a flint and steel. It does not work with fire charges either.

Steps to Reproduce:
1. Place one of the four blocks listed above.
2. Attempt to light them on their side or beneath.
3. Observe how they do not allow fire except only on top.