Media Player Classic or Videolan won't play DVD until region code is set?

I’ve been messing around with an XP-pro machine and a bunch of new (identical) DVD drives ( I think they are LG GSA-H55N).

The PC has Power DVD, Media Player Classic, and Videolan installed.

I know that all three are able to play original DVD movies.

When I swap out one drive and swap in a brand-new drive, MPC and VL seem to just hunt around and don’t play the movie. I leave it for a few minutes and still no movie. I can read the contents of the DVD (I can see the files) but it won’t play. But if I do either of the following, then MPC and VL will play:

  1. Play the movie with Power DVD
  2. Device manager, bring up the DVD - drive properties, region settings

When I do (2), it says that the drive is set for region 1, and I have 4 more changes. Note that I DID NOT set the region code. It just tells me that it’s already set to region 1. This is (was) a brand-new drive.

So if I do (1) or (2), then MPC or VL will play the movie just fine from that point afterwards (even after I re-start the machine, power down, etc). I’ve replicated this with 2 drives that were also brand new.

So my question is -> what exactly is the problem with a new DVD drive that MPC or VL won’t play it until the drive is “touched” by Power DVD or the device manager property screen?