I've only been reading the thread up to this point, but I would definitely be interested in seeing your Linux and Mac configs. Most of my network is Linux, but I have a iBook running 10.2.8 that I need tosecure on the network (and haven't even been able to get it to play nicewith WEP up to this point).
Upgrade it to MacOS X 10.3.x, WEP support is a lot better in 10.3. I used 10.3.8 on my PB 12" to connect via WEP to my old accesspoint. Also WPA is fully supported, which is even more secure, and which I use now on my new AP.
Pim