Ladders and soulsand don't mix

I was pretty sure you would be able to climb a ladder whist standing on soul sand.

However, when you stand on soul sand you cannot climb the ladder

This is how the bug can be found:
1. Place block of soul sand under a climbable ladder.
2. If done correctly you will not be able to climb the ladder.

I have attached a file showing the proper setup for this bug.