game object is not being destroyed

Hello all. This is my first question, though I have many ! So .. I have an empty gameObject prefabMusicPlayer, that carries through the scenes playing music. I wish to destroy it on the win/lose screen as the main menu has different audio. During testing this code in the GUI function worked (from the sceneScreenWin/Lose script, not prefabMusicPlayer script):

var, and Find in start function on scriptScreenWin :-

 // prefabMusicPlayer script
 var MusicPlayerScript : scriptMusicPlayer;
 
 // load MusicPlayerScript
 MusicPlayerScript = GameObject.Find("prefabMusicPlayer").GetComponent(scriptMusicPlayer);

from the GUI function on scriptScreenWin :-

 // Back Button    
        GUI.color = Color.green;    
        if (GUI.Button (Rect (10, 170, 180, 30), "Back to Menu"))    
        {    
          // DESTROY prefabMusicPlayer 
          //Destroy (MusicPlayerScript.gameObject);  // problem, added function    
          // wait so object is destroyed
          destroyAndWait ();
 
          // Load sceneScreenMainMenu    
          //Application.LoadLevel ("sceneScreenMainMenu");    
        }

But when I uploaded and ran from the website, the gameObject prefabMusicPlayer was not being destroyed. I added a function :

 function destroyAndWait ()    
 {    
     // DESTROY prefabMusicPlayer    
     //Destroy (MusicPlayerScript.gameObject);
 
     // script from unity answers advice    
     Destroy(scriptMusicPlayer.GetInstance().gameObject);          
 
     // wait so object is destroyed    
     yield WaitForSeconds (0.2);
 
     // Load sceneScreenMainMenu    
     Application.LoadLevel ("sceneScreenMainMenu");    
 }

... with no success. I found this example : http://answers.unity3d.com/questions/11314/audio-or-music-to-continue-playing-between-scene-c.html ; and added it to the scriptMusicPlayer (ADDITIONAL SCRIPT pt 1 & 2). Again, the gameObject still exists after returning to sceneScreenMainMenu, then sceneLevel1 is adding Another MusicPlayer :

the full scriptMusicPlayer :-

 // Music Player Script  (object carried through levels)
 // -------------------
 
 
 //
 var playerX : float = 35.0;
 var playerY : float = 11.0;
 var playerZ : float = 0.0;
 
 
 // ----    
 
 // ADDITIONAL CODE TO CHECK WHEN prefabMusicPlayer IS NOT DESTROYED - pt1
 
 private static var instance : scriptMusicPlayer; // use the filename of the SCRIPT , not PREFAB
 
 public static function GetInstance() : scriptMusicPlayer 
    {
       return instance;
    }
 
 // ----
 
 //
 function Awake () 
 {
 
     // ADDITIONAL CODE pt2
 
     if (instance != null && instance != this) 
          {
             Destroy(this.gameObject);
             return;
          } 
 
        // END ADDITIONAL CODE pt2     
 
 
     // carry prefabMusicPlayer through scenes
     DontDestroyOnLoad (transform.gameObject);
 }
 
 // ----
 
 //
 function Start () 
 {
     // assign the instance (don't forget)
     instance = this;
 
     // play audio if music is enabled
     if (PlayerPrefs.GetInt("Music") == 1)
     {
         audio.Play();
     }
 }
 
 // ----
 
 //
 function FixedUpdate () 
 {
     // move Music Player to audio listener 
     transform.position = Vector3(playerX, playerY, playerZ);
 
     //check if music is toggled to OFF
     if (PlayerPrefs.GetInt("Music") == 0)
     {
         // mute audio
         audio.mute = true;
     }
     else
     {
         // un-mute audio
         audio.mute = false;
     }
 }
 
 // ----

Any help would be greatly appreciated, as this would fix one of the last problems in my first game built with Unity ! (here's the project so far : http://www.alucardj.net16.net/WebPlayer.html ). Thanks, Jay.