If you were to faction change from Horde to Alliance with quests in your quest book and then back to Horde a few days later, would that bug the quests?
The reason I ask is that I did just that.
I am not 100% sure I had a certain quest taken before I faction changed but now I can't take a certain quest. The quest giver has a grey exclamation point above. I talk to him and he offers nothing. I had a friend take the quest and share it with me and it says I am already on the quest but my quest book is completely empty. I tried completing the quest despite not showing that I am on it and nothing.