Some DVDs play, some don't

[Dave M G]

localzuk,

Thank you for responding. I had been to this web site:
> https://wiki.ubuntu.com/RestrictedFormats 
But thought I would run through it again to make sure I hadn't missed 
anything.

And I discovered something very odd is happening here.

When I run this script:
sudo /usr/share/doc/libdvdread3/examples/install-css.sh
... I can get all DVDs playing.

But almost immediately after running it, I get a an "update notifier" 
alert icon in the top of my screen.

If I update, it updates the libdvdread package, and then, my DVDs can't 
play anymore.

Why is updating this package killing my ability to play some DVDs?

--
Dave M G