As you see, "target_element" will be of type "LzDataElement", and as you also see it will be compared against a "LzView" ( "immediateparent.subviews[0] == target_element " ):

"datalistselector.lzx":
[code]
<method name="findIndex" args="s"> <![CDATA[
  var target_element;
  if (s instanceof LzView) {
    target_element = s.datapath.p;
  } else {
    target_element = s.p;
  }
  
  if ( ! immediateparent.subviews[0].cloneManager ) {
    return (immediateparent.subviews[0] == target_element ? 0 : -1);
  }
  
  ...
</method>
[/code]

That's like saying "true == false" and asking yourself why this condition will never be true...
Fixed version must be:
[code]
  if ( ! immediateparent.subviews[0].cloneManager ) {
    return (immediateparent.subviews[0] == s ? 0 : -1);
  }
[/code]