Hi tdubb,
In the RHEL there are two keytool.
1.Default OS provided Keytool
2.vCloud Director - Keytool /opt/vmware/vcloud-director/jre/bin/
Check if the Keystore (certificate.ks) file is created by keytool provided by the vCloud Director, if you are not sure rename the certicate.ks to old.
And create a new certificate using vCloud keytool /opt/vmware/vcloud-director/jre/bin/keytool
Reference:http://kb.vmware.com/kb/1026309.
All the best.