I have a subtly different problem. (Mac OS X 10.6.6 and FF 4).
I don't see the NoScript icons in the Navigation Toolbar, I see the NoScript text in the Add-Ons bar. As an example, on this page -
http://noscript.net/getit - this text says:
Scripts Partially Allowed | <SCRIPT>: 15 | <OBJECT>: 0
This is true whether I have my customized settings (Control click in Tab bar and go to Customize....) set at Icons or Text.
What I'm really trying to do is get my old interface back from FF 3. I want the Back/Forward/Reload buttons to be icons and the Bookmark Bar to be text (without Icons) and NoScript to be an icon in the bottom right corner of the browser window.
I'm a completely rookie, but did manage to edit my userChrome.css file to get rid of the icons in my Bookmark Bar. Even when I disable that, however, the NoScript icons remain only text.
Any ideas?