All Jobs/Tasks are queued. But tasks completed on client systems received through site servers. "9/15/2014 11:59:45 AM","Unable to refresh task servers. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. [System.Net.WebException @ System] at System.Net.HttpWebRequest.GetResponse() at Altiris.TaskManagement.ClientTask.BaseClientTask.RefreshTaskServers(String webPath, ICredentials credentials)
It is due to certificate corruption/expired.
Replaced with the new certificate resolved the issue.
Altiris 7.5 with SSL enabled and site servers and SSL certificate installed.