Here's what I have discovered. The content for both Internet Explorer and Firefox are the same up until:
treeContent = spanNodes.item(0).xml || (new XMLSerializer()).serializeToString(spanNodes.item(0));
Following this,
treeContent has stripped out the
</span> and changed it to
/> . I'm now looking into what the XMLSerializer does and trying to discover why it works differently than .xml. Any ideas?
Thanks,