MWS and problems with Router

Help,

MWS keeps thinking that the ip should be the external IP.

I have MWS set up on a box inside the LAN at a 192.168.X.X address and the Router's IP is 64.X.X.X.

It is my understanding that MWS should have the IP of the computer inside the lan but for whatever reason I cannot force it to use that machine's IP.

I have the router set up to port forward port 80 to the machine running MWS.

I have tried running MWS with the command line options of -bind and -absolute to bind it to the 192.68.X.X ip and it still takes the IP of the router. Similarly, I have used the single homed launcher, it give the 192.68.. IP but when it starts it still has the router IP.

Any help on how to configure this or override MWS to take the IP of the machine inside the lan and note of the router.

Thanks