I have a full explanation of my issue on StackOverflow.com - if you're interested in the code, please refer here:
http://stackoverflow.com/questions/1190763/firefox-not-running-jquery-for-xhtml-output It is marked as answered, but ignore that. The gist of the problem is when I load a *local* .xml file (in firefox) the document transforms to XHTML, but the jQuery .append ('<p>Ipsum Lorem</p>') (as well as prepend, prependTo, appendTo, remove, etc) method silently fails to do anything. HOWEVER, if I construct the node to append in this manner: var frag = document.createDocumentFragment(); var p = document.createElement('p'); p.appendChild(document.createTextNode('Ipsum Lorem')); frag.appendChild(p); $('body').append(frag); It works fine. Can anyone tell me why? If I change my stylesheet to <output method="html" ... /> vs. method="xml" the jQuery code starts working again - but I am irrevocably tied to XHTML.