ICS with a usb broadband modem

I'm trying to setup up ICS on this machine for when I bring the xbox
downstairs, I've followed the instructions word for word but to no avail only
to get 'this page cannot be displayed' after a restart, the modem was
actually connected-when I hovered the mouse over the 2 computers in the tool
bar it would show the normal connection speed. Another point that I think it
could have something to do with is on the internet connection sharing wizard
I should get an option to chose which network adapter I want to use for the
internet connection, in the book I have been following it says (you may not
get this screen depending on your setup)???. After the ICS had been installed
I click on the ICS button in the tool bar and there's a drop down box with
the option connect tot he internet using: with my only option being a dial up
adapter- is that right or should I somehow be able to change that to show USB
ADSL WAN adapter-which is how I connect to the net??

Any help would be greatly appreciated
Another question how come the guide son the net say you MUST have to nic
cards? Surely that cannot be true when using a USB modem?
Thanks in advance an agravated Dan, Damn you windows!!!