problems using Yum

["Rick Lim" <ricklim telus net>]

I am trying to use Yum but I get -

[root fedorarouter ~]# yum update yum
Setting up Update Process
Setting up Repo:  base
repomd.xml                100% |=========================| 1.1 kB    00:00
Setting up Repo:  updates-released
repomd.xml                100% |=========================|  951 B    00:00
Reading repository metadata in from local files
Traceback (most recent call last):
  File "/usr/bin/yum", line 8, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 68, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 381, in doCommands
    return self.updatePkgs()
  File "/usr/share/yum-cli/cli.py", line 766, in updatePkgs
    self.doRepoSetup()
  File "/usr/share/yum-cli/cli.py", line 78, in doRepoSetup
    self.doSackSetup()
  File "/usr/lib/python2.3/site-packages/yum/__init__.py", line 93, in
doSackSetup
    self.repos.populateSack()
  File "/usr/lib/python2.3/site-packages/yum/repos.py", line 203, in
populateSack
    dobj = repo.cacheHandler.getPrimary(xml, csum)
  File "/usr/lib/python2.3/site-packages/yum/mdcache.py", line 103, in
getPrimary
    return self._getGeneric('metadata', location, checksum)
  File "/usr/lib/python2.3/site-packages/yum/mdcache.py", line 90, in
_getGeneric
    databank = self._unpickle(piklfile)
  File "/usr/lib/python2.3/site-packages/yum/mdcache.py", line 62, in
_unpickle
    obj = cPickle.load(infh)
EOFError
[root fedorarouter ~]#


Anyone have any ideas on how to fix this??