Great tool Rated 5 out of 5 stars
Superb tool, hopefully the Google pagerank will be back as well.
I miss it.
Dick van Opzeeland
We are aware of this issue and already fixed it. Mozilla team is reviewing the new version of addon and it will be available ASAP. But still you can install addon Ver 4.1(which is under review) from the url https://addons.mozilla.org/en-US/firefox/addon/webrank-toolbar-pagerank-alexa/versions/