I have hidden the plug-in in the Admin menu to everyone under Administrator role because I do not want them touching the settings of the banner or getting all confused and asking me "What's that?!" etc, etc.
But this (hiding from everyone under Admin) does something weird. Anyone who isn't logged in as an Admin cannot see the banner on the front-end of the site.
For example, someone with the role of "Subscriber" is only subscribed to posts. They cannot make any posts, but they can sure view the actual site and its content just fine, whether logged in or out, right? So why does this not happen with the content slider?
I have e-mailed the author of the slider plug-in but so far all I have got is that I have to "change my website settings". It seems there is a direct conflict between these two plug-ins.