Sometimes a NoScript user will report problems like missing icons/menus, broken permissions and so on. That never happens to most users, but if you run across a problem like this, update NoScript to the most recent development build at http://noscript.net/getit#devel and try these steps, in order, until NoScript is working right again.
1) If you have any Firefox extensions called HP Smart Web Printing, Skype, .NET Framework Assistant, or McAfee Site Advisor, then uninstall or disable them. They're buggy and known to cause problems with the status bar icon.
2) The NoScript settings became messed up somehow. Reset the NoScript Options by pressing Reset at the bottom of the Options dialog. Export your whitelist before doing that if you've added any trusted or untrusted sites you'd like to restore after NoScript is working again.
3) The extensions database is corrupted. Exit Firefox, delete the files mentioned here in this linked article, restart Firefox. Uncorrupted versions of the files will be automatically regenerated. Corrupt_extension_files
4) There might be an extension conflict. Use the Add-ons manager to temporarily disable any other Firefox extensions you have installed except for NoScript.
5) Perform a Standard Diagnostic. If NoScript isn't working by the time you get to the "Create a new profile" step, a new profile with no other extensions besides NoScript should work right.