Crash On Item Give)/give <player> 438

What I expected to happen was...:
I was messing around tryin to get the block 43:8, the 8 making the double slab block be a neat unobtainable slab block.

What actually happened was...:
I wasmessing around trying to get the sub-data right and it crashed the game.

Steps to Reproduce:
1. Enable cheats on singleplayer
2. type the command in, '/give <player> 438'
3. It crashes your game!