Aaah, I thought that option only applied to how you get notified, not what happens in a thread. I changed it to daily notification because that's what I wanted, but with notifications enabled I apparently get subscribed to everything.
That's just the default. You can change the subscription type per thread. Go to http://www.tarvalon.net/subscription.php and checkmark threads, and then "Subscribed Threads" drop down menu at the bottom right.