Updates fails with errors using yum.

[Richard Ramson]

I'm trying to update FC4T1 on a server at work, with a firewall and
proxy in place, and I'm running into problems.  When I run yum update
or yum update somepackagename, I get the following error:

yum update acl
Setting up Update Process
Setting up Repos
Traceback (most recent call last):
  File "/usr/bin/yum", line 15, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 72, in main
    result, resultmsgs = do()
  File "/usr/share/yum-cli/cli.py", line 462, in doCommands
    return self.updatePkgs()
  File "/usr/share/yum-cli/cli.py", line 956, in updatePkgs
    self.doRepoSetup()
  File "/usr/share/yum-cli/cli.py", line 79, in doRepoSetup
    repo.baseurlSetup()
  File "repos.py", line 466, in baseurlSetup
  File "repos.py", line 718, in getMirrorList
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
444, in urlopen
    return default_grabber.urlopen(url, **kwargs)
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
575, in urlopen
    return self._retry(opts, retryfunc, url)
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
547, in _retry
    return apply(func, (opts,) + args, {})
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
574, in retryfunc
    return URLGrabberFileObject(url, filename=None, opts=opts)
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
727, in __init__
    self._do_open()
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
794, in _do_open
    fo, hdr = self._make_request(req, opener)
  File "/usr/lib/python2.4/site-packages/urlgrabber/grabber.py", line
885, in _make_request
    fo = opener.open(req)
  File "/usr/lib/python2.4/urllib2.py", line 358, in open
    response = self._open(req, data)
  File "/usr/lib/python2.4/urllib2.py", line 376, in _open
    '_open', req)
  File "/usr/lib/python2.4/urllib2.py", line 337, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.4/urllib2.py", line 573, in <lambda>
    lambda r, proxy=url, type=type, meth=self.proxy_open: \
  File "/usr/lib/python2.4/urllib2.py", line 580, in proxy_open
    if '@' in host:
TypeError: iterable argument required

I ran the export ftp_proxy=proxy.company.com:80
http_proxy=proxy.company.com:80 and https_proxy=proxy.company.com:80. 
I also setup the Redhat Network Configuration with Enable HTTP Proxy:
proxy.company.com:80.  Should I be using port 80 or is there some
other reason this is failling?