Anvil Rotates while Falling

When a Anvil Fall's It Rotate's, But when hits the ground it Returns to the correct Position

What I expected to happen was...:
It would fall, in the rotation you placed it

What actually happened was...:
it rotates while falling

Steps to Reproduce:
1. Place a anvil high up
2. watch it fall
3. you might have to be facing north

Video
http://youtu.be/x7nzdPvEsD4