It seems that with the recent 1.05 beta patch the DR for armors has been severely messed up.
1. Player enchant for quality is not visible in the item's description. Notice the description and hovering info does not show fine enchantment, however the icon and the character DR information provide info to the fine quality:
2. The quality enchantments don't provide a consistent +2, +4 etc to DR. Form the picture above (notice that apart from the armor the character does not have anything else equipped) we have: slash and pierce are 18 instead of 17(15+2), shock is 7 instead of 8 (6+2).
3. Proof enchantments are no longer taken into consideration if also applying quality enchantments. We have the Saint War's armor below. Notice that compared to a standard scale armor the pierce DR is 8 instead of 5 because of the pierce proof:
Now if we apply fine enchantment we have no more pierce-proof in the character's DR information and in the item's DR information even though the pierce-proof enchantment is still listed:
Link to save: https://www.dropbox.com/s/fl76pqy1zz111oo/19763b1694ef459ab10d7c8883be9647%2010867471%20Copperlane.savegame?dl=0. Somehow saving and loading fixes bug #1, but as can be seen from the picture above there was something wrong. The other 2 bugs are not fixed by save/load.