Why is C not C?

GenericsThings.swift

//
//  ViewController.swift
//  SwiftTest
//
//  Created by Josh Holtz on 8/3/14.
//  Copyright (c) 2014 Josh Holtz. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
                            
    override func viewDidLoad() {
        super.viewDidLoad()

        var a = Maker<A>.make(); // Adheres to Base
        a.talk() // Outputs "Aaaaaa"
        
        var b = Maker<B>.make(); // Adheres to Base
        b.talk() // Outputs "Bbbbbb"
        
        var c = Maker<C>.make(); // Extends B which adheres to base
        c.talk() // Outputs "Bbbbbb" but I'm expecting "Cccccc"
        
        var d = Maker<D>.make(); // Extends B and adheres to Base
        d.talk() // Outputs "Dddddd"
        
    }

}

class Maker<T:Base> {
    class func make() -> T {
        return T()
    }
}

protocol Base {
    init()
    func talk()
}

class A: Base {
    required init() {}
    func talk() {
        println("Aaaaaa")
    }
}

class B: Base {
    required init() {}
    func talk() {
        println("Bbbbbb")
    }
}

class C: B {
    required init() { super.init() }
    override func talk() {
        println("Cccccc")
    }
}

class D: B, Base {
    required init() { super.init() }
    override func talk() {
        println("Dddddd")
    }
}

This is fixed in Xcode 6.1.1.