If you select a radio button, delete that item, and attempt to select another item, an error is generated. The action of the delete button is to delete a node in the dataset. It doesn't do anything to adjust the currently selected item.

You can test on either the shipping address or payment information pane.

The easiest fix is to test for a null image in the select() method below. This will make the error go away, but I'm not sure what happens if you:
  - select an entry
  - delete that entry
  - proceeed to checkout


classlib.lzx:

    <class name="radiobutton" onclick="select()">

        <attribute name="selectionobject" type="expression" />
        <attribute name="val" type="string"/>

        <view name="img" resource="radio_rsc" y="2"/>

        <method name="select">
          if (selectionobject.selectedItem) { Debug.write("selectionobject.selectedItem", selectionobject.selectedItem);
            selectionobject.selectedItem.img.setResourceNumber(1); <===== ****ERROR. img does not exist

          }
          this.img.setResourceNumber(2);
          selectionobject.setAttribute("selectedItem", this);
          selectionobject.setAttribute("val", this.val);
        </method>

    </class>