You may have to remove, or disable your PAM DUN Connection. My guess is that there is a conflict between the DUN Connection, and the ICS Connection.

ICS creates a LAN type connection between the phone and a computer. It does not use the Phone as a Modem.

Should just be able to:

Turn off Wi-Fi on computer, or disable it in "Network Connections"
Open Up your browser on your phone and wait for it to display a web page, and then minimize
Plug USB cable into Phone, but not into computer yet.
Start ICS on phone choose "USB" then click "Connect"
Plug USB cable into computer
ICS Network should be established
Start computer browser... And Surf...ON



Drive...ON