For what it's worth, any users who want to use almost any .xpi (firefox addon format) in a newer version of firefox, you can make most addons compatible with a few simple steps. 1. Download the addon (right click save as) instead of installing it. 2. Rename the addon to something.zip 3. Open the zip file in your software of choice 4. Grab the file labeled "install.rdf" and open it in notepad or wordpad. 5. look for the line that says: 3.1b3 6. Change the max version to something greater than your current version "5.5" for example. 7. Save the .rdf file and put it back in the zip archive. 8. Rename the archive back to the original file name.xpi 9. Drag the file onto an open firefox window, and hope everything works. Enjoy.