Thanks for the help! But my preferences are indeed in the user folder. In any case, according to the docshttp://www.sublimetext.com/docs/2/settings.html,
But I've checked the Packages/ directory and there's nothing there.
After further testing. I believe the problem was initially about the auto-detect, but I foolishly forgot to restart the program or even to close and reopen the files I was working on. That's embarrassing, but I guess I'll just know better for next time.
Thanks for your help!