The cake don't drops!

Put the summary of the bug you're having here

What I expected to happen was...:
The cake Drops itself when i breaked the block under the cake or i moved the cake.

What actually happened was...:
When I placed a cake on a block and I breaked the block, the cake don't Drops itself. Its the same when I moved the cake with a Piston.

Steps to Reproduce:
1. Part 1: Place a cake.
2. Break the cake.
3. Part 2: Place a cake.
4. move the cake with a Piston.

Notice:
Don't send me an E-Mail back, because my Mail-box crashes when there is an E-Mail in. I fix the bug.