Gamespy says I have two isp address how can I tell if I have one or two?

ok here it is I have two computers one wired into a wireless router and another connected wirelessly two the internet by a wireless usb card to the router.

but when I go onto gamespy to play a game I can play with other players but I can't host a game because of the two isp addresses that gamespy says I have how can I just use one isp address and still use both computer do I need to contact my isp provider or what can I do?

Technically you do have two IP addresses. You have a WAN IP address which has been assigned to your modem/router from the ISP's DHCP server, and then the LAN IP sent to your computer via the router.

The Game site should only recognize the WAN IP. But, to fix this, you may need to force an IP address or contact your ISP and setup a static IP so that you can have the same IP all the time. Most gamers do this.