I get the message "There are secure and non-secure items on the page. Would you like to proceed?"

The error means that there are embedded objects or HTML tags on the page that are not absolutely secure. For example, a page that is loaded securely (HTTPS) contains an image tag with the source code IMG SRC =http://www.yyy.com/image.gif. In this case, the image is using a non-secure (HTTP) protocol.