For a 64-bit machine flash player was always a problem. I followed the simple instructions on this wiki page, and everything works well
- Install flashplugin-nonfree package
# apt-get install flashplugin-nonfree
- Install the Adove Flash Player:
# update-flashplugin-nonfree --install
- Enjoy Youtube or Hulu on your Chromium or Iceweasel browsers.