Note:
When:
warning: rpmts_HdrFromFdno: V3 DSA signature: NOKEY, key ID 025e513b
Error: Could not find the GPG Key necessary to validate pkg /var/cache/yum/base/packages/xxxxxxxxxxxxx.rpm
do:
rpm –import /usr/share/doc/centos-release-3/RPM-GPG-KEY-CentOS-3