Can't play movies off external drive

Sorry if this is the wrong place to put this, but bare with me.

I have an external drive with all my movie rips. Running Vista Home Prem.

I added a second cd rom, which of course bumped the drive letters around.
ie. E: was the removable, now became F:

Just so that my media manager program wouldn’t break, I manually changed the driver letters back, assigning the new cd rom Z:

Suddenly, anytime I go to play a movie off the removable drive, I get a Region Error (which is nonsense, US movies ripped with AnyDvd running. Not to mention they played fine before). Not only that, but if I copy the folder the movie is in to my C: drive… it plays fine. So no Codec error there.

I changed the drive letters back so that they ordered normally.
ie. HDD - C: 1st CDROM - D: 2nd (new) CDROM - E: RemovableHDD - F:

Still the same problem. Region Error. VMC also errors out.

Made sure I had WMP 11, physical dvds play fine, anything ripped or copied to C: plays fine.

Any thoughts ?