The Drain rooms used to have this problem as well, regardless of the location of your login. It seems to have since been fixed, but I have only not noticed it happen in Room #3, it might still be occuring in Room #1 for all I know since my character last held a key. It occured when entering the Room, and walking through the door, closing it and locking it. Afterwards walking further into the room, the door would unlock itself.