So I recently started a thread about random crashes in-game, and somebody helpfully linked to something called FFNx, which I installed.  The game runs, and hopefully doesn't crash, but now there's pretty bad screen tearing whenever I walk around.  I read somewhere that you should modify a config file to read fullscreen=no, which I did, but it didn't fix the issue.  I also tried turning the FFNx config fullscreen=no, and that didn't help either.
EDIT: Oops, I'm a dummy, I forgot to turn on vertical sync, LOL.