Shortcode showing in posts

The shortcode is showing to my logged in members. Here is a sample of what a logged in person will see:

"Download all the images below as a zip file: [not-level-visitors] m1009 Camo Pattern [/not-level-visitors]"

Any idea why and how I can ensure that the shortcode doesn't show at all? It's fine when it's actually hiding content from not logged in people, but when they are logged in, it should be invisible.