Yes, my X5 from Netherlands with DVD changer also plays on the front screen and of course the screen is locked when driving.
One good thing, when you play Music DVD's you can actually enjoy Dolby Digital and DTS 5.1 playback.That's kinda cool. At first I thought this was not possible, but after selecting the right sound track and setting the sound to Surround it worked.

I do have an outstanding question @ BMW why the DVD changer does not play DVD's on the Back Screen. Isn't that strange?
It's simply not connect and this is certainly why I upgraded to the DVD changer, to be able to have multiple DVD's loaded for playback on the back screen.