Ubuntu and DVD playback - an issue with codecs?

As my colleague Sam Varghese has written , after nearly two weeks of flawless operation, my first Ubuntu Linux installation unexpectedly became unstable, crashed and was unable to be booted. Puzzled that an OS with the reputed stability of Ubuntu could behave like this, I searched forums and user groups for an explanation. What I found led me to believe that an open source package manager called Automatix that I installed was the cause. As a result, I am going to try an experiment: same computer, two disks, two clean installs, two operating systems - Vista and Ubuntu. But is there an issue with Linux and video codecs?

Today I will pick up my formerly partitioned Ubuntu and Windows Home Server box from my system builder. The computer has had an extra drive added so that I can run Vista on one 320GB disk and Ubuntu on the other 250GB drive.