the world fade if I place a new block from the update 1.7.1 1.7.2 1.7.4

Put the summary of the bug you're having here

What I expected to happen was...:

What actually happened was...:
if i want to place a new block from the updat 1.7.1 1.7.2 1.7.4 the world fade
but if I play Minecraft 1.6.4 the world didn`t fade

Steps to Reproduce:
1. I intsalled the update 1.7.1 .1.7.2 1.7.4
2. I started Minecraft
3. I pickt a world
4. I placet a new block from the update and the world faded