Peer Not Authenticated is more like vCenter and vCloud Director's connection is severed or the SSL session is terminated. One more common example is if you have a firewall with a TCP "reaper". E.g. if a TCP session through the firewall is on for too long, it might get disconnected.
Also, this has nothing to do with vCloud Director's personal certificates (HTTPS or ConsoleProxy).
If the error is VERY consistent, try to see if there is a schedule to it. e.g. When do backups happen? or The disconnect email comes out about every 60 minutes. If there is a systematic failure to it, then it'll be easier to see what might be related.
If a reconnect fixes it temporarily. Then the certs and credentials are fine.
Most likely there is something else getting in the way.