When using a command using metadata/datavalues of a trapdoor, it does not register it. Thus, doing "/setblock x y z minecraft:trapdoor 1" and "/setblock x y z minecraft:trapdoor 0" will both result in a closed trapdoor.

This is very annoying when making adventure maps that utilize trapdoors, as I am currently doing. Opening it by hand still works, but spawning in/testing for opened trapdoors does not work.