Problems renewing ipconfig without router

Due to some game specifics, I have to remove my D-Link DI-524UP router/switch when i play the game.

This have never been a problem before, but today I find, that the machine is not renewing any network information, when its not connected to the router.

When the router is connected, everything works fine.

Im using windows Xp sp3 with the latest Zonealarm, which was updated since i last connected without the router, but i have tried shutting zonealarm down and it made no difference.

My TCP/IP is set for auto for IP and DNS.

I noticed that when i boot the PC without the router, it still show the IP address i normally get from the router. Even if the router is not connected (and have been disconnected from before the reboot).

Repairing the connection fails, also from CMD with ipconfig - renew.

Cablewise i simply take the cable from the router and connect to my network card, so there are no problems with the cable (it works when connected to the router).

I also contacted my ISP, just to see if they had been messing with anything, but they had not.

Does anyone have any idea?

Have them reset to your computers MAC address. You should then be able to have your router clone your computers mac address so the IP will see it instead of the routers actual address.
As for the game(s) not working with the router take a look at what ports they use and open them in the routers firewall. Any game made within the past 5 years should work just fine with a router.