I did the Red Eagle Sword quest and finished it, only to have it reappear when I read the book again, only when I activate it no quest marker appears on the world map
I went to the Bards College, investigated it like the quest told me too, it disappeared and then reappeared, or never went away not sure either way, even though the messages popped up that I finished it so its another dead quest ion my menu

I can't remember the NPC's name, but its a quest you get in riften I believe, steal the horse frost, for a certain NPC from Maven Black-Briar (cant get on my xbox 360 to check what his name is right now) , and when you steal it for him, he then later appears out in front of white run stables....only he is half stuck in the ground, then as the game progresses he multiplies WTF?!? There is like 4 of him right now!?!
Also I finished the quest for the reaming members of the Bards College, the ones that require you to find their intruments, I got them AFTER I accepted the quest, not before, gave them to the NPC's, yet the instruments are still in my inventory another WTF?!?
While this game is less glitchy than Oblivion, these are still WTF glitches, legacy issues, so much for the "new" engine.