CaramelBlue on "[Plugin: WP e-Commerce] Registration Screen"

Hi again Everyone!
PLEASE can someone help with this - I simply want to enable the user of my site to have to not register after adding their product to basket & checking out so that they to go straight to Paypal.
The theme I'm using is WP-Shopified (I know it's a commercial theme but the developers haven't got back to me & I'm pretty desperate now!)
I know you can do this in the settings of WP-Ecommerce but I'm stumped with this theme; Or is there even a simple plug in that can do this?
Many thanks in advance again

http://wordpress.org/extend/plugins/wp-e-commerce/