Load Scene in AssetBundle problem

I load a scene in my AssetBundle like this:

    IEnumerator AsyncLoad ()
    {
        using (var www = new WWW("file://" + Application.dataPath + "/AssetBundles/scenes"))
        {
            yield return www;

            var bundle = www.assetBundle;

            Application.LoadLevel("Scene1");

            bundle.Unload(false);
            Debug.Log("done");
        }
    }

The problem is sometimes Application.LoadLevel(“Scene1”); works fine and sometimes Scene1 is empty. What’s wrong here?

Side note: I noticed LoadLevel destroys the current scene before loading, so the lines after LoadLevel are not being executed (since the script was destroyed). As I need to unload the asset bundle in order to use it again another time, what’s the solution?

No one?