Mplayer dvd-rw video play

Dear all,
I'm writing about an issue commented many times in the forums.
It's this: when I play the DVD I made from a Vdr recording, I get this error:
"libdvdread: Could not open device with libdvdcss"
and
"libdvdread: can't open /dev/cdrom for reading"

I obtain this when I launch the command:
"mplayer -dvd 1 -dvd-device /dev/cdrom"

Why?
The situation is this:
- All DVDs, from original ones to the dvd-r about my friend's holidays made by win**ws, play just fine.
- Mplayer 0.90 plays everything just fine.
- Mplayer 1.0 ... I can't build it.
- Mplayer 0.91 plays everything fine. EXCEPT the dvd-rw or dvd-r I record by dvd+rw-tools's growiso.

If I mount /dev/cdrom, then play mplayer -dvd 1 -dvd-device /mnt/cdrom, it works.
All the file permissions are enabled (777) both in /dev links to my scd0 and the files inside the dvd.

One can answer: "Well, play it after you have mounted it". But I can't do it for a usability issue I'm not going to explain now.
One othe can answer: "Well, why did you post this here?". And I reply: "because 0.90 version works and 0.91 doesn't. So I hope this
isn't off-topic".

Now, my question is: could anyone please tell me why mplayer says "can't access /dev/cdrom for reading"?

I use LG GSA4040B, firmware 301 updated today.
Every function of this drive works fine. Except reading its own recorded DVDs.
"dvd_test" reports no error testing the recorded dvd-r.
Both win**ws players and set-top-boxes are able to read it.
Tested medias are:
- DVD-R branded PRINCO and unbranded; DVD+RW branded TDK.
- television (vdr) recordings sized 93 and 183 MB.
Dvdrecord is not able to record, so I use dvd+rw-tools - growisofs.

Please help.
Thanks to anyone.

Obsidia