oh! Didn't notice that the AP was giving him an autoconfig IP. Forget about my previous post about gateway then as your problem is before that.

On my linksys router, you can select how many DHCP addresses are given, so I would check that. It took me a while I had selected a maximum of 2 when I added my 3rd PC to the network and it wouldn't get an IP :P

As an alternative you can specify the IP yourself (in the card properties under TCP/IP and see if you can ping 192.168.0.1 after giving yourself an IP of say 192.168.0.100