I didn't see this posted but where does it say what version of the game you have so can tell what version of trainer to get...
TokenBad99
The best recommendation I have for you is to use these rules:
If you have it installed under STEAM use the most recent trainer release for the STEAM version of the game since STEAM automatically updates your games, even if you don't want it too.
If you have it installed under Uplay use the most recent trainer release for the Uplay/Ubisoft or Retail version of the game since I don't think you can cancel updates on Uplay like you can with Origin.
The last time I had an update through Uplay I had to install the update to get it to access the game.
I know there is a game page somewhere at the beginning that says was update version is installed beyond which game control service you are running it under. I just haven't seen it yet since I haven't installed my AC-3 yet.
I hope this basic tip helps you and anyone else who has run into this confusion.
[Edited by LudicrusLeon, 2/21/2013 10:39:54 AM]