Hi,
I would suggest uninstall your current SEPM which is very old version (if you have not configured any customized settings), install latest version.
Go through following link, you will get an idea about Symantec releases.
https://www-secure.symantec.com/connect/articles/what-are-symantec-endpoint-protection-sep-versions-released-officially
Download latest version 11.0.6 MP3 at https:\\fileconnect.symantec.com, you would required serial number to download software.
Once you installed latest manager you will have to restore clients communication with manager.
You will have to run Sylink replacer tool to restore clients communication.
Go through best practice guide.
http://www.symantec.com/business/support/index?page=content&id=TECH105322&locale=en_US