How do I setup the Unity Network Connection Facilitator

I'm having an excruciating problem with Unity3D's networking features.

I've set up a Facilitator and Master Server on a publicly accessible IP address and verified that the address is reachable and the ports are open.

I'm able to have two players join and play in my game where one is the server and the other is the peer, with the server registering its game on the master server and the peer polling the master server for a game list, and then joining the correct game.

However, if I then specify the connection facilitator port and IP like this:

Network.natFacilitatorPort = connectionFacilitatorPort; Network.natFacilitatorIP = connectionFacilitatorIPAddress;

Nothing bloody works anymore! I simply get a message saying that the game isn't able to connect to the facilitator. This is misleading, because the port is open, the facilitator is running, and if I deactivate the faciliator, and run the master server on the facilitator's port everything works. The faciliator log/console window however is not reporting any activity.

The specific error I'm getting is:

"The connection request to xxx.xxx.xxx.xxx:5887 failed. Are you sure the server can be connected to?"

The master server and facilitator reside on the same server / IP address, the master server uses port 5886 and the facilitator uses port 5887 and both ports appear connectable. I'm using the default connection tester setup as I don't have 3 extra IP addresses to spare right now. The network connection tester returns the enum ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted, which suggests that NAT punch through might work, however I'm not even getting to that point when the facilitator port/address is specified.

It seems like I've left out some fundamental configuration setting, perhaps the facilitator can't run on the same IP as the master server? I dunno, I'm just grasping at straws here having already fought for 8 hours with monodevelop and the atrocity that is developing with it and Unity on a Mac. So my mind is pretty cooked at this point.

What have I missed?

[Update]

The connectivity issues appear to be caused by our windows server and firewall, as when I attempted to setup the proxy server, it also was not able to connect to the facilitator. When I mirrored the setup on my workstation the two were able to communicate. If I figure out what caused this I'll post the solution here, along with exactly how I setup the master server, facilitator and proxy, as there simply isn't any useful information out there at the moment on how to get this stuff working.