Hi
I got the same problem.
Seems that Vista won't play any Vob from external hard drive because this is
a removable drive.
I found a solution.
You have to create a junction to a folder on the external drive.

use cmd and write (from a local drive):
mklink /J movies f:\movies

Vista will create a new "virtual" folder with this new folder you can play
all DVD files.

Regards
Mastermho
"tombert" <tombert@discussions.microsoft.com> schrieb im Newsbeitrag
news:2DA70AEE-909A-46D6-880B-83404C140BD1@microsoft.com...
> DVD playback fails with Media Player with the message that region code is
> wrong. Although the region code is zero = no region. Copying the VOB files
> to
> a local hard disc the DVD plays without troubles.
>