I have been struggling with copying a DVD in Linux. I like to copy the ones I purchase in case they get damaged.
In any case, copying a dvd in kubuntu (or ubuntu) requires the installation of libdvdcss2, which isn't easily found.
I finally found the answer here:
Using the following lines, the library is installed and K3b (and other applications) can read an encrypted DVD.
sudo apt-get install libdvdread3 debhelper fakeroot
# or if that last line didn't work
As you can see, libdvdcss2 is downloaded and compiled using a script. It's not available in the repositories due to legal issues. It's illegal to copy an encrypted DVD because of widespread piracy. I believe I've read that it's ok to make a backup copy of DVDs you've purchased.
I still cannot copy some DVDs with k9copy as it seems to fail in constructing the menus for the DVD.