So I decided to go to the end and collect some more end stone for the upcoming build, and found this, now endermen steal blocks, but in the past it has been random ones here and there..this aint random as no side blocks have gone. And i definatly didn't BUILD it this way.
(http://i8.photobucket.com/albums/a28/canaryworf/end_zps1396f140.png) (http://s8.photobucket.com/user/canaryworf/media/end_zps1396f140.png.html)
all repaired now, but defo not elderman random