Problems adding NetVault Client in Client Management for a Windows Virtual Machine. (4045325)

Problems adding NetVault Client in Client Management for a Windows Virtual Machine, after customer installed the NetVault Software Client version on the Virtual Machine.
We made sure that the Windows Firewall on the Client and NetVault Server were disabled.
We then made sure that the communication from NetVault Server to Client and vice-versa was successful by entering the following commands on the NetVault Server and Client:

a] From server: ping of client hostname, nslookup of Client IP Address.
b] From client: ping of server hostname, nslookup of Server IP Address.
c] From Server CLI: telnet [IP Address from Client] 20031
d] From Client CLI: telnet [IP Address from Server] 20031

We also made sure that the ESX Server Firewall was also setup correctly, as the Client was installed there and then rebooted the ESX Server:

/usr/sbin/esxcfg-firewall -allowIncoming
/usr/sbin/esxcfg-firewall -allowOutgoing

Also re-installed the NetVault Client in the supported way and still the NetVault Client couldn't be added to the NetVault Server.