Cannot create boat using dark oak

Using Dark Oak (plus wooden shovel) will not generate a boat.

What I expected to happen was...:
Craft a boat

What actually happened was...:
A 'blank' object appeared to be in the place where the boat should be, but it was neither identifiable (hover mouse over showed no name), or selectable.

Steps to Reproduce:
1. Placing 5 planks of Dark Oak in the lower array of the crafting window
2. ...
3. ...