ZSContextWatcher implementation question

[andrewstephenson-v1]

    ZSContextWatcher* watcher = [[ZSContextWatcher alloc] initWithManagedObjectContext:defaultContext];
    NSPredicate* predicate = [NSPredicate predicateWithFormat:@"email = %@", email];
    NSEntityDescription* entityDescription = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:defaultContext];
    [watcher addEntityToWatch:entityDescription withPredicate:predicate];
    [watcher setAction:@selector(contextChangeObserved)]; // reload my UI

In an ARC project I've set ZSContextWatcher as -fno-objc-arc

My method is not firing, I must be doing something wrong.

Please advise, many thanks