Why dont you just set the router to give out static IPs? and then manually assign an IP to your xbox in the range that your router is set up. If it works do the same to all the xboxes for the lan party...
So go in to your router and specify IP address range from 192.168.1.100 to 192.168.1.150 for example and then give out statics to xoxes and your PC...
Don't forget the routers static gateway and DNS...







