Installing patch on XO-4

[forster at ozonline.com.au]

Hi

I tried installing patch on a XO-4, sudo yum install patch

I got a checksum error so I deleted /var/cache/yum/armhfp/18/fedora/packages/patch-2.6.1-13.fc18.armv7hl.rpm and tried again, it still fails

Any suggestions?
thanks 
Tony

Total download size: 94 k
Installed size: 174 k
Is this ok [y/N]: y
Downloading Packages:
warning: /var/cache/yum/armhfp/18/fedora/packages/patch-2.6.1-13.fc18.armv7hl.rpm: Header V3 RSA/SHA1 Signature, key ID a4d647e9: NOKEY
Public key for patch-2.6.1-13.fc18.armv7hl.rpm is not installed
patch-2.6.1-13.fc18.armv7hl.rpm                            |  94 kB   00:04     
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-armhfp


Invalid GPG Key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-armhfp: bad checksum on pgp message