unwanted movements when camera follows object

Hi,
i would like to add a value to the camera's position so that it can look at an object from its right side when it is moving. But when i add this small value : Vector3.right * distanceRight, the camera sometimes seems to hit something, and moves from left to right just during a short time ( like 0.1 sec ) several times on the path.

The camera looks at "targ", an empty object, which is a child of a moving sphere, and nothing is on the way of the sphere when the sphere moves, so i guess the problem comes from this line : transform.position += Vector3.right * distanceRight;

Would you know how i could get a smooth tracking with this code? (please see at the bottom, the line with / HERE / )

 function LateUpdate () {
     // Early out if we don't have the target
     if (!targ)
        return;
        
      if ( m_player.straight ){
          distance = 4.0;
         distanceRight = 0.0;
         height = 3.0;
         
      } else if ( m_player.right ) {
          distance = 1.8;
         distanceRight = 0.2;
         height = 0.6;
      }
       
     // Calculate the current rotation angles
     var wantedRotationAngle = targ.eulerAngles.y;
     var wantedHeight = targ.position.y + height;
 
     var currentRotationAngle = transform.eulerAngles.y;
     var currentHeight = transform.position.y;
 
     // Damp the rotation around the y-axis
     currentRotationAngle = Mathf.LerpAngle (currentRotationAngle, wantedRotationAngle, rotationDamping * Time.deltaTime);
 
     // Damp the height
     currentHeight = Mathf.Lerp (currentHeight, wantedHeight, heightDamping * Time.deltaTime);
 
     // Convert the angle into a rotation
     var currentRotation = Quaternion.Euler (0, currentRotationAngle, 0);
     
     // Set the position of the camera on the x-z plane to:
     // distance meters behind the targ
     transform.position = targ.position;
     //transform.position -= Vector3.forward * distance;
     
     
     transform.position -= currentRotation * Vector3.forward * distance;
     transform.position += Vector3.right * distanceRight; /*  HERE  */
 
     // Set the height of the camera
     transform.position.y = currentHeight;
 
     // Always look at the targ
     transform.LookAt (targ);
     
 }

Thanks