Why does this not work?

Hi,

Why does the first script not work but the second one does by calling pauseFlightPath01 first then calling pauseFlightPath02 ?

 #pragma strict
 
 var minWaitTime : int;            // Minimum time to pause flightpath
 var maxWaitTime : int;            // Maximum time to pause flightpath
 var planeSound : AudioClip;
 var useFlightPath : GameObject;    // Flighpath to send message to
 
 function Awake(){
 
 }
 
 function Start() {
 
     audio.volume = 0.5;
     audio.loop = true;
     audio.clip = planeSound;
     audio.Play();
     Invoke("pauseFlightPath02", 0);
 }
 
 function Update () {
 
 }
 
 function pauseFlightPath02(){
 
     var randomWaitTime : float = Random.Range(minWaitTime, maxWaitTime );
 
         yield WaitForSeconds (20); // Length to end of flightpath
         audio.Stop();
         useFlightPath.SendMessage("Pause");
         yield WaitForSeconds (randomWaitTime);
         audio.Play();
         useFlightPath.SendMessage("Play");
 
     Invoke("pauseFlightPath02", 0);
 }

 #pragma strict
 
 var minWaitTime : int;        // Minimum time to pause flightpath
 var maxWaitTime : int;        // Maximum time to pause flightpath
 var planeSound : AudioClip;
 var useFlightPath : GameObject;    // Flighpath to send message to
 
 function Awake(){
 
 }
 
 function Start() {
 
     audio.volume = 0.5;
     audio.loop = true;
     audio.clip = planeSound;
     audio.Play();
     Invoke("pauseFlightPath01", 0);    
 }
 
 function Update () {
 
 }
 
 function pauseFlightPath01(){
 
     pauseFlightPath02();
 }
 
 function pauseFlightPath02(){
 
     var randomWaitTime : float = Random.Range(minWaitTime, maxWaitTime );
 
         yield WaitForSeconds (20); // Length to end of flightpat
         audio.Stop();
         useFlightPath.SendMessage("Pause");
         yield WaitForSeconds (randomWaitTime);
         audio.Play();
         useFlightPath.SendMessage("Play");
 
     Invoke("pauseFlightPath01", 0);
 }