I was playing with a friend some redstone things. (Armor stands via summon)
I tried to set an invisible armor stand with a base64-head.
~1 minute later i noticed some bugs in rendering, Water was in the air (not full blocks, only visible sides)
Then the glass panes started to bug, too. (appearing in the air, rotated not normal)
If i go into thirdperson, it gets more buggy:

• Players start to rotate, move and disappear
• Players-Models start to mess up (Feet are walking on head, sometimes whole player upside down)
  Every of these bugs are only in some chunks, and they depend on camera rotation.
  They are moving synced with the camera, no wheird blinking stuff.

I asked some friends to test it, it happened the same for all of them.

If you want to see it, simply got to: andy.mymc.info:25565 (My ingame is _GLaD0S)

Oh, we also changed the biome in this area.
I will try to download the map/play in singleplayer (check if it's still there), or copy to another server.