Anyone else have this happen with certain enemies? Just goes straight through without dealing damage. I have a game saved right before a Dragon Priest and can replicate the problem.

I've made sure I'm not just missing, picture after using TFC 1 to freeze an arrow in flight -

http://i.imgur.com/F4f5X.jpg

Made no contact, did no damage.

I'm not using anything but visual and interface mods. I am using the archery .ini tweaks for more realistic arrow flight, but I doubt that's it since I can hit most things fine.

It happens. It's a bug, and seems like the first shot misses some times for me at least. The worst is when you line up a sneak shot and the enemy magically slides to the left or right. Or the arrow hits an invisible wall..

Try aiming for the knee next time.

Happened to me multiple time in a row on a draugr overlord, i did some test by reloading and re-shooting, it happened multiple time. I finally succeeded after several try. (i'm 100% sure i wasn't missing, i usually never miss my target, and that particular draugr made me "miss" 6-7 time)

I havent had this happen, but I've run into invisble walls that I have to go around.

This can happen. But I've never experienced this myself with creatures before, no.
I know of arrows going through humanoid enemies who are laying against a wall, leaning over a ledge or sitting on a chair.
Sometimes trolls and falmer can replicate this behaviour, but that looks to be more about their slight shifting when sitting.

Did you really need to post something so obvious?

Actually..... I was gonna post that, but you beat me to it.

It happened once for me. Just a random bug

That happens to me as well, pretty strange.

Yes, I've had it happen a few times.

I had the opposite (sort of) problem with my first character .
My arrows wouldn't go through , they would bounce off .
They would still do a little bit of damage , but only about 10% of normal . It didn't happen all the time , only in random dungeons , but in the dungeons it happened in , it was like that all the way through .

I even had that with a sword once, in that case, it turned out that the bandit who I saw attacking me was not the actual bandit, apparently the real bandit, due to some bug, was 3 feet away and invisible, luckily my dog Meeko was able to spot him.

I never experienced this bug. The only one I have is with people leaning against walls. Their 'hitbox' get swallowed by the surrounding wall and trying to hit them with an arrow usually results in said arrow bouning back as if it had hit a hard surface.