I've noted that the "blow by blow" attack (3d6 sonic) using a "+3 Shock Adamantine Returning Throwing Axe of Bleeding" is not doing sonic damage.
From the combat log:
(Combat): You attack Witch Doctor Kneeza. You roll a 17 (+25): you hit!
(Combat): You hit Witch Doctor Kneeza for 1 point of electric damage.
(Combat): You hit Witch Doctor Kneeza for 3 points of damage
(Combat): You help Witch Doctor Kneeza with Threat.
(Combat): You hit Witch Doctor Kneeza, but did no damage.
(Combat): You hit Witch Doctor Kneeza for 17 points of slash damage.
I tried multiple times on different enemies. The sonic damage part of blow by blow never did any damage.
Any bards using different types of weapon see similar results?