I'm trying to use my mbp's airport connection to pass internet to my desktop via Ethernet. I've followed a few tutorials online, but nothing seems to work. Right now I have the desktop and mbp hooked up to a hub and the airport is connected wirelessly to a router in another room. Internet Sharing is on, 'sharing from Airport' is selected, and share to computers using 'built-in ethernet' is selected. Am I missing something?