OK, working now
So big thank you to l3mce.
Not to sure how or when I did the right thing that started it working. Lots of updates, installed the medibuntu keyring, added medibuntu to sources.list, left the repo's alone as 0810 RC's repo's are different from the wiki one, RC looks like a later version. Then suddenly at another attempt at installing the packages it started downloading the packages and we were sweet.
Curios, though, the sources.list on my md and the sources.list on the Core are now different (medibuntu) but the Core has always been able to play DVD's.
A question: during the installation of w32codecs I got a " Suggested packages: gstreamer 0.10-pitfdll"
Should I install this?
Thanks again l3mce