Rated 3 out of 5 stars

After the installation of the last version of firefox 5, the tool bar not appear. Also it-s impossible to instal the tool bar again.

This review is for a previous version of the add-on (1.1.9). 

As noted above this is a reviews section and not the best place for support. The best place for support is my site where it has a solution to this problem:

http://chrispederick.com/work/web-developer/help/#buttons

If this doesn't work for you then please see some other suggestions in the forums that have worked for others.