I hear ya knives. I'm having the same problems that you are encountering. My brother has a PS3 and all his trophies have unlocked with no problem. I'm thinking like you are maybe its time to make a change
I got this problem once with Skate 3 DLC. I could not redo them in the same Story. Here are the steps I followed. I don't know what causes it but the fact is that he unlocked the Achievements only locally.
1. Delete the DLC/Save-Game from HDD/Memory Card.
2. Delete Gamertag from HDD.
2. Clear System Case: Dashboard > Settings > System > Storage > Push Y for Device Options
If it's correct after this the Achievements who where not Properly Registered to LIVE are back Locked and you can redo the accomplishments needed for the Achievement. If this not helps I advise you to wait here for a Answer from an Official Support Member
or Call the Official Support in your Country.
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