Ubuntu 9.10 Karmic, An error occurred, Your GStreamer installation is missing a plug-in

I'd receive the dialog message "An error occurred, Your GStreamer installation is missing a plug-in" when attempting to play a DVD ripped ISO file in Totem movie player.

*** UPDATE ***

Run this line in a terminal (highlight with mouse, and in terminal, push both left and mouse buttons down at the same time... Or.. highlight with mouse, hit Ctrl-C for copy.. then in the terminal, hit Ctrl-Shift-V to past):

sudo aptitude install ubuntu-restricted-extras

sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list &&

sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update

sudo aptitude install libdvdcss2

sudo aptitude install non-free-codecs

sudo aptitude install gstreamer0.10-ffmpeg gstreamer0.10-plugins-ugly gstreamer0.10-plugins-base gstreamer0.10-plugins-good gstreamer0.10-alsa mpeg2dec ffmpeg libdvdcss2 totem-gstreamer libdvdread4

Then run:

sudo /usr/share/doc/libdvdread4/install-css.sh