I found Treasure Map II at... I looked at it, recognized the location, put it on my "to do" list.
With the map in my possession, I entered Honeyside. Then, I immediately heard the sound of a book closing and received the message, "Treasure Map II Removed". I've been in and out of Honeyside with other treasure maps without having them removed. In fact, I had Treasure Map III on me at the time. I had not claimed that treasure either.
Anyone else seen that or know why it happened?

It just happened to me yesterday (as of this post) - I lost X and VII, one per entry into Proudspire manor in Solitude. What happened was that apparently I'd taken a quest somewhere (from that nice guy in Windhelm, I believe) that caused the bandits in Cragswallow cave (I think it was called that, it's just north of Ansilvund) to respawn, and the bandit leader carried this map on her person. I killed her for my quest and found the map for X again on her corpse. Odd.

Maybe there can only be one? /highlander