Test for over UI 4.6 works on Mac doesn't work on iPad

I have created a small script that tests for whether the mouse is over a UI element, and returns that state. I then use this to determine whether to raycast.

It works properly on the Mac, but when testing on the iPad, it doesn't.

Any idea what I might be doing wrong?

 using UnityEngine;
 using System.Collections;
 using UnityEngine.EventSystems;
 
 public class touchTest : MonoBehaviour {
 
     public int overUI = 0;
 
 
     public int ReturnUIState (){
         return overUI;
     }
 
     void Update () {
         if (EventSystemManager.currentSystem.IsPointerOverEventSystemObject ()) {
             // we're over a UI element...
             overUI = 1;
             }
         else{
                 overUI = 0;
             }
     }
 }

Thank you!