yum problems on install of FC2

Hi

I just did a fresh install of FC2 after having used FC1 for a number of
months. After the install I went to do a yum update having and receive
the errors below (completely unhelpful error messages). I have set my
http_proxy exactly as it has always been set. Any help would be welcome.

Jonathan.

Unable to find pid
Gathering header information file(s) from server(s)
Server: Fedora Core 2 - i386 - Base
Traceback (most recent call last):
  File "/usr/bin/yum", line 30, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum/yummain.py", line 233, in main
    clientStuff.get_package_info_from_servers(serverlist, HeaderInfo)
  File "/usr/share/yum/clientStuff.py", line 846, in
get_package_info_from_servers
    progress_obj=None)
  File "/usr/share/yum/clientStuff.py", line 1327, in grab
    bandwidth, conf.retries, retrycodes, checkfunc)
  File "/usr/share/yum/urlgrabber.py", line 237, in retrygrab
    progress_obj, throttle, bandwidth)
  File "/usr/share/yum/urlgrabber.py", line 314, in urlgrab
    fo = urllib2.urlopen(url)
  File "/usr/lib/python2.3/urllib2.py", line 129, in urlopen
    return _opener.open(url, data)
  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