I have posted about this as well. I think it has something to do with the quester's level (7 in this case) compared to the quest level. It would be nice to know how that works, if someone has an idea...

Edit: It seems the level of the quester has nothing to do with it. Apparently some quests yield no XP and/or fame.

The quest The Arctic Wolf Cloak also does not give xp or fame.

In that case, I think the Quest Complete! screen shouldn't show up for those quests, or at least shouldn't show the xp/fame portion of the screen.  I like the idea, but seeing a big screen highlight a nonexistent reward is kind of a bummer, and confusing as well.

The "Hunger Pains" quest also gives 0 xp and 0 fame, with no reward other than the xp you get for defeating the ogre.  That is, if you choose to fight the ogre and save the inn's customers.  I didn't try letting the ogre eat some of the customers, in that case I guess you get the ogre as a reward.