Stair Glitches

Dafuq? It could be something from your Video Card (I noticed you run on a MAC OSX).

No it wasn't a problem with the video card. My computer is fairly new.

Still, there can be many compatibility issues. What's your Java?

1.7.9 I believe.

Ah, dang it, MAC OS X Java D:. Could be a problem with the compatibility between your vid card and your java.

There wasn't really a way to reproduce it, it just happened.

I tend to notice that this happens when there is a lot of entities around. An example; in my world where I play around with villagers, and there is a lot of em, I see this visual glitch a lot, however, otherwise in normal villages or anywhere else, this rarely happens. Not only does it do this in the game but in the inventory, the stairs, slabs and sometimes fences flash oddly for a brief second, and again it only happens with a lot of mobs around, least for me.

The stair glitch is not Mac related, its just in the video rendering of Minecraft. I have a new Mac and a Windows and same on both. Video bug (Minor)

This was fixed already.

This issue has re-appeared in 1.6.4. I have built an Enderman Farm in the end. After leaving via portal left by killing the dragon then returning a bit of time later to the farm, some of the stairs had glitched out. After pillaring up to such stairs, a block-update fixed the rendering.

I'd also like to point out that there were quite a few entities(enderman) in the farm upon my return, which confers that entity count may be part of the issue.

Also, occured in a windows env.