Mostly there are just problems with the quest log, I think (like the Raanaar quests not showing up properly). After talking to Tax (ie once you have freedom to go wherever you want), head north west a little bit to the temple complex and explore there first (click the message board 4 times). That should avoid glitches with finding quest items before getting the quest, though even in that case dropping the item and talking to the NPC is usually enough to trigger the quest option.
