That sounds like your browser isn't properly setting the cookie that would track your cart contents as a buyer; however, I was unable to reproduce that issue myself with any of the cart buttons on that page, so the issue is probably something peculiar to how you're testing things.
Sometimes testing your cart at the same time as editing your account or product settings can confuse the cart you're testing with, so try clearing your browser cookies (or at least delete any cookies for e-junkie.com and venderapublishing.com); this will fully reset the cart in your browser, so you can be sure you're testing your cart from a clean slate.
Also bear in mind, E-junkie Cart needs to be tested using a regular Web browser program on a live sales page with a domain name in the URL (even if you don't link to that page from any public pages of your site yet); it won't work properly on a "local" copy of the page that's only stored on your own hard drive, nor using the "preview" mode of any Web design software.