Explorer Mac loses track of the element when it's been removed. So in this browser elements don't stay in hyperspace after they've been emptied from the innerHTML.
When you remove an element by
innerHTML='' it's possible
to re-append the element to the document. In Explorer Windows, though, the text goes missing.
This is a complicated bug. Pay close attention.
<h4 id="testHeader">. We create a pointer by means of
pointer = document.getElementById('testHeader');.
The text disappearance is obviously a bug; if the element is available it should also contain its child nodes.
It's also interesting to note that when you remove an element through
the element is not trashed but continues to exist in DOM hyperspace. It's there, but it's not
attached to the document, so it's invisible.
That's why 'Move header' works the second time.
The pointer still points to the element in hyperspace, and it's re-inserted into the document.
Without the pointer this wouldn't work:
work, because the test header is not part of the document any more.