My first Linux machine was a 2Ghz Celeron. I was running Vista and subsequently Dual Booted with 8.04. Then I sold it to my son and just put Ultimate 1.9 on it because he did not want to buy a license for Vista or XP. He was the one that noticed he could not play Commercial Copy Protected DVD movies. I found out that css2 was needed and once installed, it allowed him to play Commercial Copy Protected DVD's. Up to that point, he could only play Decrypted DVD's.
I tested my machine and discovered I had the same problem. I added CSS2 and I could not play the Commercial DVD's. I then was encouraged to use VLC Media Player instead of Totem. I was told to go into conf-editor, Desktop, Gnome, Volume Manager, and change the default for Autoplay DVD and Autoplay VCD, from Totem %d, to /usr/bin/vlc dvd:// and /usr/bin/vlc
vcd://. From that point on, Totem still launched, when a DVD was inserted, but it would not play and I could not force it to play. I changed the settings back to Totem %d, but Totem still would not play the dvd.. I was amazed to find how much trouble it was to finally make VLC the default player for inserted DVD's. Google is wonderful when it comes to finding links to problems and solutions. I had to edit a list file and change some of the lines from Totem to VLC. In the meantime, I could not use Totem until you found the solution.
I am new to Linux, even though I spent my last 20 years , at Kodak, in IT. I am now retired and can enjoy playing with other things besides Windows.
There are so many apps that do similar things, so I am trying to sort out the differences and picking my favorites.
My next challenge was to get MythTV to work with my WinTV HVR 1600 card.