I saw the bug report on the tech/age issue, but ran into a different one. One of the quest parameters is that I cannot change my state religion. However, I convinced one of the neighboring civs to convert to mine and got the quest failed message. I don't remember whether this happened on the same turn that I received the quest, but it was definitely within a turn or two of the quest kicking in. I don't have a saved game file to upload, unfortunately, so there it is for what it's worth.