Okay, so I've installed uSkyblock and Worldguard to protect it, but nobody can break blocks on their islands not even me unless I'm op. If Someone can help that would be great. My GroupManager file is here. GroupManager: http://pastebin.com/RyacipTh
I'm sorry to say but uSkyblock is not very good considering the things that are happening to it at the moment, Try Joe's Sky Block That supported well, I use to use uSkyblock But didn't work properly so i switched to Joe's Skyblock http://dev.bukkit.org/bukkit-plugins/joes-skyblock/
If you still have problems with uSkyblock contact me on my own forum(see signature) and I will help you out.
I'm guessing you messed with __global__ flags. I currently have a server running uSkyBlock + WorldGuard and it is working quite well. LHammonds