DVD Player Error -70001

I bought an external USB DVD-ROM drive for playing region 2 discs (we're big Doctor Who fans). I was using an old external DVD burner that I switched to region 2 and it worked great. This new drive plays the little "don't copy this" warning at the start of the disc, then DVD Player goes off into never-never land.

If I try to choose another title, it goes off into never-never land again and comes back with a popup that says "DVD Player encountered a system error Error -70001". From what I've seen, Error -70001 is a problem with region coding, but the drive is already set to region 2.

Is there a way to find out exactly what the problem is?