Switching off shipping in WP-eCommerce

Hi,

My client needs to work out the shipping only after someone has made a “purchase” on his site so by default, this option needs to be switched off and yet, when I switch shipping off, I still get shipping options coming up everywhere. I could hide this with CSS but if the option to switch off shipping is there, I would like to be able to use it.

Is there something else I need to perhaps switch off/set?

Thanks