Door bounding boxes are 0.005 of a block too thin
So, this is probably one of the most ludicrous bug reports you've seen, right? Door bounding boxes are off by 0.005 of a block.
In PC (and according to the wiki) they are 0.1875 blocks thick (3/16). In PE, they are 0.1825 blocks thick. Maybe a typo, (probably) affects nothing but custom server movement anti-cheats causing the odd glitch when walking through doors.
Reference: http://minecraft.gamepedia.com/Door#Barrier
EDIT: This also affects trapdoor bounding boxes.
This information was obtained using IDA.