To make it a short answer.
Plug your computer's ethernet cable directly into the modem
in place of the router you're bridging to.
Hard code an ip address in your Network Connections
according to your modems "LAN" side address.
For the ActionTec I have it's 192.168.0.1
So on my W-XP desktop,
I hard coded 192.168.0.90/255.255.255.0/192.168.0.1
And it worked!
Your mileage my vary.