Question: No matter what I do the posse achievements won't unlock, such as Over 9001 and Put the Posse on a Pedestal.  I've done it a million times -- help!

Answer: The posse scoring achievements are part of the Liars and Cheats pack, but they show up for all Gamertags and PSN IDs.  To unlock these achievements, you will need to purchase and download the Liars and Cheats pack even though it is possible to generate a posse score without them.