didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler Not called - ios

Question

I am creating an application that receives push notifications, and once recieved a push notification it will process this normally if the application is active, or process it in the background if it is not running.
The most annoying part - The app works fine when I am in Development mode and running through XCode. But when I put an Ad Hoc build up, the app only receives the notifications if the app is running. My Code to handle the notification is below, can someone please shed some light on this:
-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
MySharedClass *shared = [MySharedClass sharedManager];
UIApplicationState state = [application applicationState];
if (state == UIApplicationStateActive) {
shared.localNotif = userInfo;
if (shared.localNotif) {
[shared ReceivedPushNotification];
}
} else {
__block UIBackgroundTaskIdentifier background_task;
background_task = [application beginBackgroundTaskWithExpirationHandler:^ {
//Clean up code. Tell the system that we are done.
[application endBackgroundTask: background_task];
background_task = UIBackgroundTaskInvalid;
}];
//To make the code block asynchronous
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//### background task starts
NSLog(#"Running in the background\n");
completionHandler(UIBackgroundFetchResultNewData);
shared.localNotif = userInfo;
if (shared.localNotif) {
[shared ReceivedPushNotification];
}
while(TRUE)
{
NSLog(#"Background time Remaining: %f",[[UIApplication sharedApplication] backgroundTimeRemaining]);
[NSThread sleepForTimeInterval:1]; //wait for 1 sec
}
//#### background task ends
//Clean up code. Tell the system that we are done.
[application endBackgroundTask: background_task];
background_task = UIBackgroundTaskInvalid;
});
}
}