Rated 4 out of 5 stars

Oo0Bailey0oO: had the same problem, it's easy to fix though. Navigate to ~/Library/Application Support/Firefox/Profiles/(yourprofilenamehere)/extensions/{9bc51d13-3849-4541-a69c-da418934ca05}/chrome/content/ and edit overlay.xul with your preferred text editor - the menu is easy to spot.