I started a character in Limsa Limosa, and leveled to 15 as ACN in that general area. As soon as I'd unlocked the airship, I traveled to Ul'dah, switched to GLD. I obviously didn't have story-line quests in that area, but I was getting side-quests... until I played the Silver Bazaar quest-line out to its end, and suddenly, no more side-quests in Thanalan zones.

Is this a bug?