/(^o^)\ Rated 1 out of 5 stars

とりあえず治るまで4.9.10に戻すか、他のアドオンに乗り換えたほうがいいね。
WindowsXP Firefox16.0.2

4.9.10
https://addons.mozilla.org/ja/firefox/addon/video-downloadhelper/versions/

This review is for a previous version of the add-on (4.9.11.1-signed).