We've tested transactions on your site using your E-junkie account, and we also tested with another method that allows us to test a checkout from our cart using your PayPal email but not referencing your E-junkie account at all, and in both cases PayPal's checkout site applied its own shipping charges rather than the shipping calculated in the cart.
These results, along with the fact that none of the other 10,000+ sellers using our system have reported any similar problems, indicates that something in your own PayPal account settings is causing PayPal's checkout site to override or compound the shipping calculated in your E-junkie cart -- actually, it seems to be adding an extra $5 for the first item and $4 for each additional item in the cart. We would recommend consulting PayPal support to see if there might be any settings other than what you'd already found that could account for that.