Circle hooks

In the past I've used circle hooks, with live bait, to catch fish in saltwater.  No setting of the hook, just reel in.  Most if not all the fish were hooked in the side or top of the mouth.  I've never used them in freshwater until yesterday.  I bought a package of snelled circle hooks, size 8.  I caught a few crappies and catfish.  Most were hooked in the mouth, but a few swallowed the hook.  I always thought that this wasn't supposed to happen with circle hooks.  My question is:  do you think you get better hook-ups with the circle hooks in freshwater?

i often use Gamakatsu circle hooks for fishing live bait. i usually use size 8 hooks for trout and siize 1/0 for catfish. about %90 of the time it seems like the fish will get hooked in the corner of the mouth which makes it a lot easier to release fish unharmed. fish will get hooked deeply though if you let them take the bait too long.