That "test" only implies a number is incorrect in the add-on, nothing more should be read into that message. Norton, and many other security software vendors, don't usually support pre-release Beta version web browsers. Firefox only checks the '''maxVersion''' specified in the install.rdf file for the extension that is installed in Firefox, which is a very minor point as far as "compatibility" goes, and that is "set" by the developer of the add-on. The burden for true compatibility is on the developer.