The OnMouseOver and OnMouseEnter functions cease to work when screen.lockcursor = true

I've tested this with a new gameobject. Added this code:

 function OnMouseEnter (){
   Debug.Log("MouseOver");
   if(Input.GetKeyUp("e")){
     Debug.Log("Pressing e");
     if (TestCloseEnough()){
       Debug.Log("close enough");
     }        
   }
 }

While i have my inventory open, the Screen.lockcursor is set to false so the player can click things and move them around. (Then the prints show up) but as soon as the player exits inventory (i.e. screen.lockcursor = true) the onmouseover just doesn't register anything.

Ive tried this both with onmouseover and onmouseenter

using Unity 3.5.0b6