(Nsmenuitem): Setter manquant ou variable d'instance

Je rencontre une erreur étrange:

import Cocoa
import Foundation

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

@IBOutlet weak var window: NSWindow!
@IBOutlet weak var statusMenu: NSMenu!

let statusItem = NSStatusBar.systemStatusBar().statusItemWithLength(-1)

func applicationDidFinishLaunching(aNotification: NSNotification) {
    let icon = NSImage(named: "statusIcon")

    statusItem.image = icon
    statusItem.menu = statusMenu
    // Time for constant repeat
    NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerRepeat", userInfo: nil, repeats: true)
}

// Method to call the tracking core
func timerRepeat() {
    //....
}

@IBAction func frontEnd(sender: NSMenuItem) {
    var targetURL : String = NSBundle.mainBundle().resourcePath!
    targetURL = targetURL + "/" + "front.app"
    let workspace = NSWorkspace()
    workspace.launchApplication(targetURL)
}


@IBAction func menuClicked(sender: NSMenuItem) {
    NSApplication.sharedApplication().terminate(self)
}   
}