Robert Anthony Whitelock
Comments
I was Attempting to create a Wither auto-killer with TNT and an obsidian box and when i tried to spawn a wither in a hole in it it wouldn't work. so i want outside the box and tried again and the wither spawned successfully. i decided that there must be a bug as the Wither spawned outside fine with no blocks under the soul sand but in the obsidian box in the hole it wouldn't work as there was obsidian under the soul sand "arms". after further testing i found that it was true with any block. this was confirmed for me in the already mentioned Mind-crack episode when it wouldn't work for them either with the tall grass underneath it.
Also in 14w30c The Wither would move around to attack things before it exploded after being spawned. i do not know if this was fixed in a later version.