I opened my database and edited the wa_settings table to include the "www". Then I had my friend try it by selecting the product and clicking on the "PayPal" button which sent him to paypal. and when he was done there and was sent back to my site he had the same result of "cart is empty" message. I then opened the site in DW and edited the site (site management) so the url also included the "www".
as previuosly stated I have a test product under the catagory of tools for $0.01
my site is
Thanks for your help