Tibrinn's Quest
 

Hi,
for this quest I gathered the Mithril Plated Girth (from Grazhak the Berserker) and the Slime Crystal Staff.
I gave the Mithril Plated Girth to Tibrinn Ember in Rathe mountains. Then I gave him the Slime Crystal Staff.
But I got nothing, no message, no experience, no reward, no Sap Sheen Staff as I expected to receive.

What am I missing? Is this quest broken? What should I do to get the Sap Sheen Staff?