[CentOS] yum behinf authenticated proxy

Hi,

> 
> http_proxy=http://user:passwd@proxy.foo.com:portnumber
> 
> 
> 
> for your reference:
> http://www.google.co.uk/search?q=yum+authenticated
> +proxy&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a

Yes, i've searched google and found that before posting here.
The problem is that yum now doesn't work anymore:

"[root at localhost ~]# yum update
Setting up Update Process
Setting up repositories
Traceback (most recent call last):
   File "/usr/bin/yum", line 29, in ?
     yummain.main(sys.argv[1:])
   File "/usr/share/yum-cli/yummain.py", line 97, in main
     result, resultmsgs = do()
   File "/usr/share/yum-cli/cli.py", line 477, in doCommands
     return self.updatePkgs()
   File "/usr/share/yum-cli/cli.py", line 955, in updatePkgs
     self.doRepoSetup()
   File "/usr/share/yum-cli/cli.py", line 71, in doRepoSetup
     yum.YumBase.doRepoSetup(self, thisrepo=thisrepo)
   File "__init__.py", line 225, in doRepoSetup
   File "repos.py", line 533, in baseurlSetup
   File "repos.py", line 842, in getMirrorList
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
583, in urlopen
     return default_grabber.urlopen(url, **kwargs)
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
741, in urlopen
     return self._retry(opts, retryfunc, url)
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
702, in _retry
     r = apply(func, (opts,) + args, {})
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
740, in retryfunc
     return URLGrabberFileObject(url, filename=None, opts=opts)
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
893, in __init__
     self._do_open()
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
960, in _do_open
     fo, hdr = self._make_request(req, opener)
   File "/usr/lib/python2.3/site-packages/urlgrabber/grabber.py", line 
1059, in _make_request
     fo = opener.open(req)
   File "/usr/lib/python2.3/urllib2.py", line 326, in open
     '_open', req)
   File "/usr/lib/python2.3/urllib2.py", line 306, in _call_chain
     result = func(*args)
   File "/usr/lib/python2.3/urllib2.py", line 491, in <lambda>
     lambda r, proxy=url, type=type, meth=self.proxy_open: \
   File "/usr/lib/python2.3/urllib2.py", line 498, in proxy_open
     if '@' in host:
TypeError: iterable argument required
"

Regards,
Mário Gamito