I have upgraded to ubuntu 12.04 for my Pangolin Performance laptop. I want to be able to play DVDs but cannot. I have been to several Ubuntu forum sites and allowed all their instructions implicitly, including downloading the libdvdcss-2 repository. When I insert a dvd into the disk drive, it whirrs but nothing happens. The disk does not appear on nautilus and cannot be accessed by vlc or movie player. Can anyone help?