There seems to be something wrong with the extra damage portion of the druid natures warrior.

Your melee and ranged attacks deal an extra 1d6 damage against enemies with less than 50% health.

The extra damage seems to only proc infrequently despite mobs being below half health. It does occasionally happen but its certainly not every hit while the mob is under 50% health. I would say its more like 5-10% of the hits when the mob is under half health. Something a bit more odd about it is that sometimes when it does proc and does force damage the immune message comes up beside the force damage and the mob takes no extra damage. (this is on normal mobs where you would expect them to take force damage)

Difficult to say if the rest of the natures warrior is working correctly. I wonder if the extra sneak attack stacks with items or the half elf rogue dil.