When Iron Golem starts do any action (Walking, going to kill hostile mob...), game crash. When reopening the world, game hold for few seconds and then crash again. World keep crashing until iron golem stop doing his action.

What I expected to happen was...:
The game should keep working, when iron golem starts doing any action.

What actually happened was...:
When Iron Golem start doing an action, game crash, when reopening the world, game hold for few seconds and then crash again. This pushes me to downgrade to 1.4.2.

Steps to Reproduce:
1. Craft iron golem
2. Spawn spider or any other mob that golem gonna kill.
3. When iron golem start walking toward the mob, game crashes.

I'm sending crash report below and video demonstration here : http://www.youtube.com/watch?v=H-BSNHaugDk&feature=youtu.be