urllib, urllib2 HTTPDigestAuthHandler() bug?

[Stephen Steiner]

Has anyone tried opening a URL that requires authorization?

Here's my test program (I've removed the real password etc.) but this 
is pretty much straight out of the top of the urllib2.py file:

import urllib2

# set up authentication info

authinfo = urllib2.HTTPDigestAuthHandler()

authinfo.add_password('realm', 'host', 'username', 'password')

proxy_support = urllib2.ProxyHandler({"http" : "http://ahad-haam:3128"})

# build a new opener that adds authentication and caching FTP handlers
opener = urllib2.build_opener(proxy_support, authinfo, 
urllib2.CacheFTPHandler)

# install it
urllib2.install_opener(opener)

f = urllib2.urlopen('http://theaddressoftheDAVserver')

buf = f.read()
f.close()

print "read %d bytes" % len(buf)
print buf

And, here's what I get when I run it...

Traceback (most recent call last):
   File "urltest.py", line 19, in ?
     f = urllib2.urlopen('http://idclinux2/dav')
   File "/usr/local/lib/python2.2/urllib2.py", line 138, in urlopen
     return _opener.open(url, data)
   File "/usr/local/lib/python2.2/urllib2.py", line 322, in open
     '_open', req)
   File "/usr/local/lib/python2.2/urllib2.py", line 301, in _call_chain
     result = func(*args)
   File "/usr/local/lib/python2.2/urllib2.py", line 794, in http_open
     return self.do_open(httplib.HTTP, req)
   File "/usr/local/lib/python2.2/urllib2.py", line 788, in do_open
     return self.parent.error('http', req, fp, code, msg, hdrs)
   File "/usr/local/lib/python2.2/urllib2.py", line 348, in error
     return self._call_chain(*args)
   File "/usr/local/lib/python2.2/urllib2.py", line 301, in _call_chain
     result = func(*args)
   File "/usr/local/lib/python2.2/urllib2.py", line 400, in 
http_error_default
     raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error 401: Authorization Required
Exit 1

Clues, anyone?  Has anyone used this?

Thanks in advance for any help.

Steve