Camera Orbit on Left Click problem

I have this code, and it works for the most part. the only problem is that it only updates its position when i'm turning the character or turning the camera. if i make the character walk forward or backwards, the camera will maintain it's current position until i force it to rotate, then it will snap back to the character. Some help, please?

 var target : Transform;
 var zoom_distance = 5.0;
 var zoom_distanceMin = 5.0;
 var zoom_distanceMax = 20.0;
 var camera_height = 1.0;
 
 var xSpeed = 250.0;
 var ySpeed = 120.0;
 
 var yMinLimit = -75;
 var yMaxLimit = 75;
 
 var positionDamping = 2.0;
 
 private var x = 0.0;
 private var y = 0.0;
 
 private var zoom = 0.0;
 
 private var last_rotation : Quaternion;
 
 private var doing_smoothfollow : boolean = false;
 
 function Start () {
     var angles = transform.eulerAngles;
     x = angles.y;
     y = angles.x;
    
     // Make the rigid body not change rotation
        if (rigidbody)
         rigidbody.freezeRotation = true;
 }
 
 function LateUpdate () {
     if (target) {
         // Scrollwheel to set camera distance
 
          zoom_distance = Mathf.Clamp(zoom_distance - Input.GetAxis("Mouse ScrollWheel")*2, zoom_distanceMin, zoom_distanceMax);
 
         if(Input.GetButtonDown("Fire2")){
         // The Unity script inverses the x and y.
 
         // Also, start adding the mouse rotation to the current transform Euler Angles
         x = transform.eulerAngles.y;
         y = ClampAngle(transform.eulerAngles.x, yMinLimit, yMaxLimit);
         }
     
         if(Input.GetAxis("Fire2")){
 
         // Add mouse values to rotation, based on the previous camera rotation
 
         x += Input.GetAxis("Mouse X") * xSpeed * 0.02;
         y -= Input.GetAxis("Mouse Y") * ySpeed * 0.02;
 
         // Clamp the y so weird things don't happen
 
          y = ClampAngle(y, yMinLimit, yMaxLimit);
 
         var rotation = Quaternion.Euler(y, x, 0);
         var position = rotation * Vector3(0.0, camera_height, -zoom_distance) + target.position;
         transform.position = position;
         transform.rotation = rotation;
         last_rotation = rotation;
         }
     
     //Smooth follow if turning or tilting or the camera hasn't reached it's last rotation (before it was moved)
 
     else if(Input.GetAxis("Horizontal") || Input.GetAxis("NoseThrust") || doing_smoothfollow){
 
     //TODO: Implement doing_smoothfollow to let camera settle down behind ship
 
     wantedRotationAngle = Quaternion.Angle(transform.rotation, target.rotation);
     
     // Quaternion smooth follow
 
     transform.rotation = Quaternion.Slerp(transform.rotation, target.rotation, positionDamping * Time.deltaTime);
 
     transform.position = transform.rotation * Vector3(0.0, camera_height, -zoom_distance) + target.position;
 
     last_rotation = transform.rotation;
     }
 
     else {
         //Follow player even when not pressing 3rd mouse button
 
         transform.position = last_rotation * Vector3(0.0, camera_height, -zoom_distance) + target.position;
 
         transform.rotation = last_rotation;
     }
 
     }
 
 }
 static function ClampAngle (angle : float, min : float, max : float) {
 
     if (angle < -360)
         angle += 360;
     if (angle > 360)
         angle -= 360;
 
         // Hacked to get it working with the Euler angles. Could be better I guess...
     if(angle > 360+min)
     
         //angle = 180 -angle;
         return angle;
     if(angle > 180)
         angle = -angle;
     return Mathf.Clamp (angle, min, max);
 
 }