Ok i will try and report back but i have 2 questions:
1- must i install this on the core AND any MD (through moonXX)?
2- do i risk breaking my system following the steps in my link?
You need to install it on any machine where you wish to playback DVD's or rips of DVD's. In fact there are still relatively few DVD's that will not be playable with libdvdcss. We always recommend that you use regionset on your DVD drive and set it to a specific region before using it for encrypted DVD playback. If this is not done then this can increase the likelihood of a libdvdcss failure message.
All the best