2D Object Movement, PingPong issues

I'm working on a Top-Down 2D, Raiden Style Shooter. The player Ship basically stays withing a clamped range, and doesn't move through game space. Enemy objects spawn off the screen, then move down to a random 'near' range before they start firing/moving.

I have it set up to have the enemies pingpong when they hit the near range, however, for some reason the enemies jump position at the start of it, leading to a choppy transition between their approach and the start of their patterns. Here's the code - tell me what you think is wrong please.

 enum enemyRange {Far =0, Near =1}
 var positionSet: boolean;
 //var player : Transform;
 var initialPosition : Vector3;
 var enemyWiggle : Vector2;
 var nearRange : float;
 static var eRange = enemyRange.Far;
 
 var enemySpeed : float;
 function Awake() {
 nearRange = Random.Range(3,4);
 }
 function Start () {
 
 }
 function Update () {
 if (!positionSet) {
 CheckStatus();
 }
 if (positionSet) {
 
 EnemyPong();
 }
 
 //Initiates the range testing
 switch (eRange) {
 
 case enemyRange.Near:
 break;
 
 case enemyRange.Far:
 
 transform.Translate(-Vector3.forward*(enemySpeed)*Time.deltaTime);
 break;
 
 }
 }
 function CheckStatus()
 
 {
 if ((transform.position.z > nearRange)&&(!positionSet)){
 eRange = enemyRange.Far;
 positionSet = false;
 }
 else if (((transform.position.z <= nearRange) && (eRange==enemyRange.Far)&&(!positionSet))){
 //print (transform.position.z + "should be where it pings to");
 positionSet = true;
 
 eRange = enemyRange.Near;
 initialPosition = transform.position;
 
 
 
 }
 }
 function EnemyPong() {
 transform.position.x = Mathf.Clamp(initialPosition.x + Mathf.PingPong(Time.time * enemySpeed, enemyWiggle.x),-4,4);
 transform.position.z = Mathf.Clamp(initialPosition.z + Mathf.PingPong(Time.time * enemySpeed, enemyWiggle.y), 1,49);
 
 }