paypal order summary is empty

Hi all, I have just put up my first WordPress site and have installed the eshop plugin. On my checkout I added the ‘buy now’ paypal button which links to paypals site. The problem is the items in my shopping cart are not transferring from my site to paypals site. I have tried to research the error of my ways, but am not having any luck trouble shooting what I have bungled. Any help would be much appreciated!