Comment 1 for bug 1358070

Confirmed on Firefox 33.0+build2-0ubuntu0.14.10.1, xul-ext-unity 3.0.0+14.04.20140416-0ubuntu1. The browser console shows the error repeating 200 (?!) times:

NS_ERROR_XPC_SECURITY_MANAGER_VETO: unity-global-property-initializer.js:238

    observe: function (aWindow, aTopic, aData) {
        // This can be dispatched from either the inner or outer window
        if (aWindow.window == this._aWindow && aTopic == "dom-window-destroyed") { <------------
            Services.obs.removeObserver(this, "dom-window-destroyed");
            this._loseInterest(true);

            this._removeAllListeners();
            this._callbackManager.releaseAll();
        }
    },