Help tethering Internet not working

[pjstock]

I cannot seem to get the Tethering working on my new HTC One X+.

I use my smartphone's mobile data to provide internet to my laptop and desktop when away from my wired home base.
with my old Nexus S, I just attached the phone via USB left the USB connection option OFF and Voila! Internet.
the

I expect my failure is due to pilot error, as the USB Network Sharing options seem to be more complicated on the One X.
But I've tried all three options (Smat Network Sharing, USB Tethering and Internet Passthrough) but none give my laptop Internet via tethering.
Although Wifi Hotspot works fine.
what am I doing wrong?

Peter