Bukkit

I am using the latest version of the plugin and have been using it fine up to now.
Whenever a player right clicks a join sign it says you have joined the arena but you stay in the same world and it doesn't teleport you to the arena. I checked the console for any error messages and Whoooaaaa, slight issue.
From my experience I believe its a teleport event error but your the experts on this plugin so... here is the error http://pastebin.com/ckJ2tvw5
Thank-you :)