Rated 5 out of 5 stars

I used http://userstyles.org/styles/45652/firefox-4-autohide-navigation-bar-alternative and http://userstyles.org/styles/45531/firefox-4-autohide-navigation-barbut this seems better and maybe there will ever come settings, too :D

BTW: Why navigation bar pops up if I right click in a page?

This review is for a previous version of the add-on (2). 

The navigation bar appears when opening a context menu in-case you prefer to click the buttons in the toolbar as opposed to the ones in the menu.