Problem Sharing Wireless with Mac

I thought I was having problems getting internet to work on the Vista system of my MBP. I recently discovered that that's not quite the case. I had no problem getting wireless to work on a public network. However, I cannot get it to connect to the network I have set up with my iBook G4 sharing it's ethernet via Airport. It gives me an error about network security not meeting requirements or something, but gives me no options to change it. I also cannot get internet to work with it when connected directly to the ethernet either. I have tried downloading all the Boot Camp drivers, installing them again, deleting and then reinstalling, rebooting the computer, and reinstalling Vista. None of this has had any effect. Is there some way I can get Windows to connect to the wireless network from my Mac?