All was working well on Firefox watching music videos on Youtube. I decided to try an addon ¨Youtube Downloader - Media Downloader 1.0.8¨ I installed it and now all the Youtube windows for watching music videos are black... I have removed ¨Youtube Downloader - Media Downloader 1.0.8¨ but still no good. Any ideas. I have KDE Mageia 3. Thank you
Edit - It looks like this program ¨Youtube Downloader - Media Downloader 1.0.8¨ disables JavaScript. Once I enabled Javascript within Firefox all was fine.