Albretch,

Not quite sure here, but, I think, your problem has been resolved through a numerous amount of other posts, i.e. the topic, and issue, has come up many times before...

Have you installed the libdvd library? My guess is, no. DVDs are encrypted, and you need a "codec" or decryption method to play them.

You may want to do a search for this libdvdcss - and, considering I did it already, I got 35 topics that were found, you should be able to locate the lib, and get your player running...

Yes, Xine, kaffeine, mplayer, xawtv, and a host of "other" DVD players are available to watch those files, media. You do not open and view the files, but, rather, the "players" open the DVD and know how to handle the movies. The same holds true for AUDIO CDs, you dont open them, but, use a Audio CD Player program to open them, and play the audio files. You only "open" data CDs, to view there contents.

So, here is the scoop:
DVD discs = use a DVD media player to view them.
AUDIO discs = use a AUDIO CD media player to play them.
DATA discs = open and view them with Konquerer, Mozilla, etc...

If you attempt to "open" a DVD or AUDIO disc, you will only see files, and not be able to play, or listen to them. To view or play these media discs, you need to use a player program. For DVDs, you need the decryption library installed to be able to play them. If after the library is installed, you can not play a DVD, then, start up a Konsole screen - the little monitor icon along the bottom of the screen, and type xine - then attempt to play the DVD, you will see information output on the screen, possibly more information on what the problem is, and we can better locate the cause, from that output...

Hope this helps,
Ms. Cuddles