[Vaprakgruumsh]

Several factors, I believe can lead up to this.

One, what is your skill in the weapon you're using to attack? If it's not that high, you're going to miss - and if you hit - probably not skilled enough to penetrate. I put my points (at that level) for fighters, into whatever weapon they used, and close combat.

Another factor is, what you're fighting. You may need to do Armor Melt to make it easier to hit them.

(For that matter, I just entered the Sea Caves, and came across Adamantium Slimes - where I was normally doing 50 damage, I was suddenly doing 3 damage, if I was lucky!) So some monsters simply have higher density (another good example is the Rock Crabs, same situation - armor melt did no good).

So there's a number of things that could be leading to this. But more than likely, I'd say it's how yer distributing yer points.