500 Error with certain User Agent strings from w3.org

Hello.  I'm encountering an error retrieving the following document:

http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd

When the user agent string Java/1.6.0_16 is passed in..  Details of  
the request/response at the bottom of this email.

I can successfully retrieve the dtd at this URL if a 'normal' browser  
user agent is passed in, for example, "Mozilla/5.0 (X11; U; Linux  
x86_64; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.517.41  
Safari/534.7 "

A reproducible test case is as follows:

WORKS: wget http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
WORKS: wget -U 'Mozilla/5.0 (X11; U; Linux x86_64; en-US) AppleWebKit/ 
534.7 (KHTML, like Gecko) Chrome/7.0.517.41 Safari/534.7' http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
FAILS: wget -U 'Java/1.6.0_16' http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd


GET /TR/xhtml1/DTD/xhtml1-transitional.dtd HTTP/1.1
User-Agent: Java/1.6.0_16
Host: www.w3..org
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive

HTTP/1.0 500 Server Error
Cache-Control: no-cache
Connection: close
Content-Type: text/html

<html><body><h1>500 Server Error</h1>
An internal server error occured.
</body></html>

Received on Friday, 5 November 2010 13:59:23 UTC