Problem with granting priveleges other than 'Public'

[Quoted] I have created a WebDB site and added some content (a menu with a few reports). If I set all priveleges to 'Public', users can use the components. However, if I set either the execute priveleges or the menu item priveleges to anything other than 'Public' no users can either see or successfully execute them, even if the user is specifically granted permission to view the menu or execute the component.

This is holding true for me both for priveleges specifically granted to the user, or for priveleges granted via a role. I need to be able to make certain website content available to the public and restrict other content to one or more groups.

What am I missing here? Can anyone assist?

Thanks much in advance!!