Rated 4 out of 5 stars
I would love it more if the back/forward key where not broken up. After installing this theme it broke down the back/forward button into two separate ones.
I love the roundness of the tabs and the single Firefox button converted to a Firefox icon.
The back/fwd buttons are not broken (at least shouldn't be). It's a design choice to have two separate buttons. Maybe something went wrong, please post a support reply and attach a screenshot.