It doesn't work anymore with html5 player by default.... Rated 2 out of 5 stars

And i don't know what to do.....:(

I have last official Firefox version and windows 7 x64

This review is for a previous version of the add-on (2.9.2.1-signed). 

Hello, it works fine for me, for example here: http://www.reddit.com/r/videos/

What Firefox version and OS are you using?