Hum... Take a look if your content can't just be wrapped with <![CDATA[
and copied.See this answer (I know, CDATA abuse and everything, but OP don't want to parse the XML at all, just append it directly to the DOM).
Update: What actually worked
Change your call to the get
method so it interprets the response as pure text and let JQuery create the DOM Tree for you. Have a look here.