probs with matshita dvd/cdrw combo drive and mplayer

[Madn3SS <icitizens@gmx.net>]

greetings...

i've git some serious problems with my matshita dvd/cdrw combo drive in my acer travelmate 225xc.

the cd/cdrw part works properly, but everytime i want to watch/load a dvd with mplayer, i get an error like:

 couldn't open dvd device: /dev/dvd

i changed the device in the mplayer config to /dev/cdrom, but then the error looks like:

 couldn't open dvd device: /dev/cdrom

watching .vob files from dvd works fine... but the menu doesn't work, that suxxx.

what's my mistake? do i have to mount the dvd in a special way? what device should i choose?  i don't have a clue...

PLZ HELP...

THX
Dom