OBVIOUSLY I RESTARTED, AROUND 10 TIMES BOTH FIREFOX AND WHOLE PC, AS I SAID IT SIMPLY DOESN'T WORK Rated 1 out of 5 stars

It works only the first restart, then it doesn't work anymore and needs to be reinstalled everytime.

This is very simple extension, just a few lines of code. If it doesn't work, may be it conflicts with the other extension that you installed.
Or you can try the first version https://addons.mozilla.org/en-US/firefox/addon/double-click-to-reload-tab/versions/?page=1#version-1.0.0
If it still doesn't work, I can't help you anymore. Sorry!

Rated 1 out of 5 stars

Simply doesn't work on Firefox v7.0.1

Please fix and update it!

I'm using Firefox 7.0.1 now, and it still works. The Mozilla reviewed it. Please restart your browser after installing.