Oh that one i hated that bug in single player when i was trying to make a awesome house. But the bug goes when you place 2 wood or iron doors then put pressure plates then the doors would glitch up then it would stay open when not on the pressure plates, but the moment out got on 1 it would close. And to answer your question i don't know if they fixed it.
Thats because double doors hinge at different sides.. Following some South East Rule. If u were to power both doors with redstone, one would be open and one would be closed because of the orinetation of the doors. To open both, one needs to be powered, and one not powered. So the dilema with having pressure plates at the doors, is that the plates power when stood on, so one of the doors will be backwards.
This is because of a little piece of information that not a lot of people know: When you place double doors, you are actually placing one of the closed doors in the "Open" state. This being the case, a pressure plate will "Open" the opened door and revert it to the closed state, while stepping on the pressure plate later will "Close" the closed door in a similar manner. If you use double pressure plates and a NOR Gate, you can make the system work. Otherwise, sorry.
