no!!!!!!!!!!!!!!!!!! I could not install firefox addons for sometime now. I was able to on my Windows machine.. But not on Linux.. Then I found this: http://ubuntuforums.org/showpost.php?p=3965149&postcount=21 So, I disabled ipv6 on firefox and now I can install addons. However, Windows' Firefox can install addons with ipv6 enabled.. Weird..............