Rated 5 out of 5 stars

disable it... enable it and refresh youtube
should work i just tried it
if not close firefox and restart browser but the first one should work fine :D

This review is for a previous version of the add-on (3.1.4.1-signed.1-signed). 

There's a new build on www.glimmersoft.com :). It should be up on Mozilla before long too. Thanks!