When you click on the checkout paypal button it just closes the popup shopping cart and does not popup a new browser window asking for paypal login?
Purbread, as far as your site the button doesnt open or change anything for me. I looked at your code and maybe it is becuase it can not be inside a form like that, i dont know. Did you try getting your button code again and seeing if you have all the stuff from that? It seems you have something missing in the line of code - unless it is somehwere else and I missed it. for example, where is the HREF part of the code where is specified your ejunkie ID and product code?