Or rather, DVDs from outside of my region.

I am in North America (region 1), so those play OK.

I also have some Euro DVDs (region 5). I went to matrix menu and set DVD region code to 5 and booted but the stupid thing says "TV System doesn't match" or something to that effect.

Now I don't know if this has anything to do with video system: the DVD's could be in SECAM, and in Matrix menu there's only choices for NTSC, PAL, PAL60.

Obviously, these play without a hitch on a PC.