I made a world in minecraft 1.7.10 and played it in minecraft beta 1.7.
I converted it to the new minecraft snapshot.
I was 3000000+ and 2000000+ blocks away from spawn.
It maybe my computer as it is old and slow.
The sand teleports randomly and looks weird while falling.
The sand still works normally and lands normally.
It may because of minecraft beta.
I also saw the world loading weirdly but it might be because of beta 1.7.