While onsite trying to remotely push a Backup Exec 2010 R2 remote agent, we were getting a lot of the "error code 1603" messages, which stated:
"Error connecting to the remote server. Ensure the server is available, has WMI enabled, and is not blocked by a firewall. 1603."
It seems like this is the likely problem, mentioned in the below Symantec technote:
Our workaround was to just install the client manually on each server that wouldn't connect, instead of going through all the steps mentioned in the above technote.