1)You could create a new key and a new certificate request in order to get another certificate for the new SCA. Most Certificate Authorities require that you pay for every machine that will contain the cert regardless if you are using the same cert and key. The purchase of this additional cert may put you in compliance with that agreement if you were not already (assuming your CA has this requirement).
2)You could contact your CA and revoke the present certificate and re-submit a certificate request. This may be the least expensive option. Regarding the problem with the PEM certificate, the usual problem is that the password or the passphrase was not correctly entered, or not entered at all. You may check details of how to do that at:
http://www.cisco.com/en/US/customer/products/hw/contnetw/ps792/products_configuration_guide_chapter09186a0080579e92.html
