The snow layer blink in different status in the inventory

What I expected to happen was...:
The snow layer stays in 1 pixel Y-Axis

What happened was...
The snow layer switch, 1 pixel; 3pixel; height of a water block;...

Steps to Reproduce:
1. I was under Y=64, in a river biome.
2. Look in creative at the snow layer in "decoration blocks"
3. Glitch of height.

Sometimes it was blinking every half-second
But sometimes it stop or do not work...
It is really glitchy and annoying for the eyes, was I helpful?

VIDEO: http://www.youtube.com/watch?v=0cxCXBBs7xY There is no lag or freeze when the player stop instantly moving, I was just pressing "alt"

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