When Render Distance is set to something above 5 certain areas of land become cloned along a large area, the clones are ghost blocks.

This is a bug where When Render Distance is set to something above 5 certain areas of land become cloned along a large area, the clones are ghost blocks. 14w31a is the only version i have found it in mostly but i think it has been a bug since the new chunk loading/rendering was added since it seems to change the clones based on where i am looking.