I thought it would be cool if I had a monkey head be crushed, but the fracturing process didn't workout. The monkey head geometry didn't look smooth and the physics didn't look quite right. Other than that I think it looks cool.
Sorry for replying so late. What I did was I applied the game logic to the head before i fractured it.
Keep in mind that the monkey head model is not a closed mesh! The eyes are separate parts, that will distort various effects and simulations, for example a glass material on it will look wrong or things like you experienced them will occur.