This is causing the WebDriver test imported/w3c/webdriver/tests/is_element_enabled/enabled.py::test_xml_always_not_enabled to fail, but because we fail to find the node first.

>       element = session.find.css("note", all=False)
E           NoSuchElementException: no such element (404):

body       = {'using': 'css selector', 'value': 'note'}
err        = <NoSuchElementException http_status=404>
method     = 'POST'
response   = <Response status=404 error=<NoSuchElementException http_status=404>>
self       = <Session 2d4c898d-9ba1-40e7-867c-3c99b339dcdb>
url        = 'session/2d4c898d-9ba1-40e7-867c-3c99b339dcdb/element'

This is because document.querySelector('note') is returning null.

The document is just:

<?xml version="1.0" encoding="utf-8"?>
<note></note>

Saving that to a file and opening it in both ff and chrome, I can get the valid node by calling document.querySelector('note') from the inspector console.