I only had 3 skulls to find, a couple of missions to gold star and a few more bonus objectives to get before completion.
Turned to xbox on today and id lost everything, all missions are listed as uncompleted, all skulls, logs, objectives listed as locked
Seriously annoyed, was so close to those achievments and then to have all progress wiped absolutley sucks.
Safe to say i wont be playing through the game again to unlock them.