Some of the damage enchantments seem to not work properly. For example, pounce and backstabbing don't work. If you're not familiar with these enchantments, pounce increases damage output on a sword while in the air. Backstabbing increases damage by 20% per level, and 40% per level if you're sneaking. Both of these enchantments don't directly add to the swords damage, but rather are multiplicative, so I believe it might have to do with that. On a side note, I have been using the overenchanter to make them go above max level, but I have also tested it at max level and it still doesn't work.