Bukkit

When I Make the join sign the sign just stays like  a normal sign is there a command I can just do to join?

http://pastebin.com/057QBphn

I have the same issue, the console says im using a null world, i don't understand why if im using the same name my map has.

here's the config file:

http://pastebin.com/Hp1hEDkk