andrew Kane

I've also seen this. It didn't spawn that way, but it grew in my farm normally, and did not break when the sugarcane block beneath it was broken. I was able to break and pick up the floating sugarcane after taking the screenshot, so it wasn't purely a visual artifact.

I didn't f3 or seed when I took the first screenshot, but I went back to the same spot and did those things.

http://i.imgur.com/ShL9vCR.png

http://i.imgur.com/80uVM7f.png

My stair disappearance issue was with saving / loading the game, which may be equivalent to loading / unloading the chunk.