Internet should be working but it isn't

I really have no idea what's happening. We got two computers here, a Mac and PC. For some reason, the connection worked right away on the Mac without the need of configuring anything... but not on the PC. I used the Network setup wizard, chose the second choice and it completed succesfully. My PC has its IP, DNS... everything. I event went ahead and used ipconfig /all here's a screenshot of the results.

http://i108.photobucket.com/albums/n19/Rovelius/screenie01.jpg

I sure don't have a LOT of experience setting up networks but from what I know, this here should be workng all right... I'm hooked to a router which in turns is hooked onto our modem, using DHCP and completely configured to automatically assign an IP to up to 3 computers. The PC is running on XP Pro SP2, all antiviruses/spywares disabled, no firewall at all. When I check the connection's status, I can see my PC sending packets but not receiving anything - however, when using the Broadcom Management panel and pinging my router, it does come back to me which I think eliminates the possibility of my network card being broken.

If you guys got any ideas, it would be very appreciated.