Hey Hey,

You may want to check out these sites.. they may or may not be of use, but they've got some data.
http://www.allensmith.net/Windows/ICS/xpICSmtu.htm
http://www.annoyances.org/exec/show/article04-105

I used to have a cable connection sharing from one computer to another no problem, I also setup a friends house to have a gateway using ICS and the rest into a switch connected to that gateway without problem. However when I switched to DSL, I couldn't get it to go. We even called tech support finally and they said that ICS doesn't work properly with DSL because of the PPPoE (may just not have wanted us to use more than one computer). Luckily though our DSL provider allows for up to 8 IP addresses, so we were able to just pick up a switch and use that. I wish you luck because I have found it's not an easy thing to do, however the workaround in the first link I posted may work for ya.

peace,
HT