First,
EaseUp. Putting URGENT in the title will
reduce the chance of getting a useful, quick answer.
Your XML, as posted, does not seem to be readable. My quick
test was to try to get Internet Exploder to display it, and it won't.
Also, the URL
http://www.w3c.org/TR/xhtml1/DTD/xhtml1-transitional.dtd produces a "forbidden" response, if entered into a Web browser.
Maybe the problems, therefore, are not with your parsing, but with the XML itself.