I emailed my question to tech support and received a reply. I think there may be some confusion. I installed the e-junkie Add to cart button on each item and it is showing correctly. At the top of each page (aside from the Add to cart button) there is a View Cart button that a buyer can access wherever they are on the site.
This is the button I'm having issues with. Yes, I realize this is a PayPal button. I DID try to install the e-junkie button but am having issues with it. When I installed it, it didn't show my logo. Plus the checkout page opened up as a small page, not a full, separate page like it should be. It also affected ALL my other items in the same way.
I included the script you suggested and it showed the logo ok, but the checkout page is still opening up as a small page, as are all my other items.
It also seems to do something to the margins on my website.
So yes, I am leaving th PayPal cart until this can be resolved. Hopefully this can be soon, as I don't want to confuse my customers.