Last night I realised that the custom world name feature hadn't been working since I implemented it, so this update should now completely rectifiy that and fix any issues with it.
If World_Name in the config does not match the world name that the player is stood in, then the plugin will ask the user to correct it in the config file.
For 99% of people this fix will be completely invisible, but for those of you that use this plugin on worlds with custom names, I hope this helps!