This is because the port 4747 is not open between the user. You can try to test it with telnet. Telnet perfmano1 4747 if you see a blinking curser the port is open. If this is a 2008 server Firewall is on by default.
This really looks like port 4747 is block somewhere between the client and the server. The screen you see is the Plugin trying to Tunnel and being you are using IIS and IIS isn't setup to tunnel it is failing.