Spigot 1.8.8
Precious Stones 546
Vault 1.5.6
This config:
http://pastebin.com/GZFwWTw0

Put a diamond ore on the ground and place double doors.
Login with another account and sneak and rightclick at the same time.
You will get through the doors easily.
In addidtion to that, you will get "you cannot teleport inside a field....message

After setting
?prevent-teleport: false (was true before)
it's working again.