When accessing my site securely (using https), it indicates that the page contains secure and non secure items. Why is this happening?

The page you are trying to access refers to some links which are not secure (is trying to load other HTML objects, e.g. pictures, which are not secure). This is most likely caused by some image tags like this:

• non-secure img tag example: <img src="http://somedomain.com/images/image.jpg">

You have to either replace "http" with "https" or try to use just relative paths in your html (which is better) as below: