I know this is an old thread, but I am having the same issue. I have searched the forums, and from what I have read, I haven't been able to learn how to get past this problems.
Any suggestions would be welcome.
Here's the situation and desired setup. Split house, sharing internet. The other part of the house has a wireless modem that we connect to. Unfortunately we have trouble connecting, and staying connected, at least in the living room, however connection is fine in the bedroom. We would like to use an old computer to connect wirelessly, then share to our own wireless router, and then the other computers in our part of the house can connect to our own router.
WiFi in other side of house >> Computer on our side >> Our own router >> Our computers
When I try ICS I get the error as described above. Not sure what I am missing.