Problems rinning two games on my Home Network
 

I have two copies of MOHAA and have them on my two home computers which are connected to a Linksys Router and to Cable. The games run fine individually on GameSpy but I can't use both computers together, One always gets Timed Out. I've set up gamespy seperately with both computers using different usernames. I have no firewalls except for the router itself. I'm using Win XP Home edition. How can I play both MOHAA from my network. Settings are " obtain an IP address automatically" and "obtain DNS server address automatically". Thanks for any help.