Internet Sharing - help a noob out

Alright, so here's my deal today that I'm having some PITA with - internet sharing. I have a PC right next to my G5 that I love to game with, but unfortunately its USB wireless connection no longer is working. So, I thought I might save myself a little bit of trouble by using the G5 to passthrough the wireless connection over an ethernet cable to my PC. However, I pop into Sharing and turn internet sharing on from Airport to Ethernet 1 and Ethernet 2 - however my PC doesn't get a connection. So, I'm not exactly doing something right, but I can't figure out what.