I burned my project onto a dvd-r using dvd studio pro 3, and when I tried to watch it back on my tv, the player says it can't play it due to the region setting.

The project's region codes are at the default setting (all the regions selected except for "reserved").

What could be causing this issue? I was under the impression that dvd-r media can't have any region codes.

Thanks

Yes you can burn region codes (as in theory you could macrovision)
on your own DVD just fine. This information is stored within the
IFO files in the VIDEO_TS directory on a DVD disc. Which are just
"files".

I'm not sure what could be causing your problem if all regions are
enabled. Sounds like an issue with your DVD player. Do you have
a way to check the disc on multiple players? That could perhaps
point to whether the disc or player is to blame.

If you e-mail me the IFO files from your disc I should be able to
see which regions are enabled.

Thanks for your help, but I was able figure out what was wrong --which was just a stupid mistake on my part.

I formatted the disc from an older build that for some reason didn't have region one checked. When the new disc still didn't play, even though I had went back and corrected the problem, that's when I thought that there might be a serious issue.

I burned the disc from the newer build and now it plays fine.

Thanks again.