The Error

[ben@www ~]$ sudo rpm -Uhv http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm
Retrieving http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm
warning: /var/tmp/rpm-xfer.QD2HVP: Header V3 DSA signature: NOKEY, key ID 217521f6
Preparing...                ########################################### [100%]
   1:epel-release           ########################################### [100%]
[ben@www ~]$ yum search dupclity
Loaded plugins: fastestmirror
Error: Cannot access repository dir //var/cache/yum/epel


The Fix:
rpm -e epel-release
[ben@www ~]$ sudo yum upgrade yum
 rpm -Uhv http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm

The confirmation:
[ben@www ~]$ sudo yum install duplicity