authenticateHandler was only handling 1 of the 3 scenarios identified in the documentation discussion (http://developer.apple.com/library/ios/#documentation/GameKit/Reference/GKLocalPlayer_Ref/Reference/Reference.html#//apple_ref/occ/instp/GKLocalPlayer/authenticateHandler). The gameCenterManager:availabilityChanged optional delegate was not fired as a result of this issue. Simply added a statement to re-check the availability after the authentication handler completed successfully
Merge pull request #1 from jonswaff/master

Fixed Bug where the availabilityChanged delegate did not fire