Check out https://bugzilla.mozilla.org/show_bug.cgi?id=414612. Basically, in FF2,

getElementsByTagName

for xml elements with a namespace (like "abc:TheTag") would return those elements if you called

getElementsByTagName("TheTag")

. In FF3, you get nothing for that call - instead you must call

getElementsByTagName("abc:TheTag")

, like in IE.

Here's how it affects jQuery:

http://brh.numbera.com/experiments/browserdemos/firefox-bug-414612-jquery.html

It used to be that you could get the namespaced xml elements by saying

$('TheTag', data)

, but now there's no way at all to get at those namespaced items.

This is related to jQuery issue #155 and #1826