Comment 16 for bug 502426

I solved the problem in #15.

I followed the steps in the following thread:

http://ubuntuforums.org/archive/index.php/t-1440147.html

All the relevant steps to getting DVDs to play in Ubuntu 10.04 seem to be listed in one place there.

Unfortunately for me it was a long process of trial and error rather than access to that thread!

What seems clear is:

-Ubuntu did not think the DVD drive's region was set to [4]. It reported region [2]. Windows 7 had successfully played a region [4] disc on my laptop but the drive did not seem to 'remember' the region setting under Ubuntu.
-Ubuntu was able to recognise the drive type (Matshita UJ892) using System -> Administration -> Disk Utility.
-I got garbled (presumably incorrectly decrypted) video from Totem and VLC Media Player until I deleted the folder shown in this command:

sudo rm -r ~/.dvdcss

and restarted Ubuntu.

This last step is crucial, allowing DVD decryption capabilities to be rebuilt.

Overall I feel this was an unnecessarily complex procedure to get usable DVD video on Ubuntu, but it is working flawlessly now.