I'm guessing due to how long the last replay is getting achievements with trainers is dead huh? I really should have finished getting them all a while back haha.
What I've noticed is.... the kill achievements work, (I just ran the first 7 missions of Halo 3) got 'Going Bananas' and 'Gruntageddon' however the mission achievements 'Finish Sierra 117' didn't. As I'm playing the game for the fun it's no problem for me.
Thank you all the developers of these cheats!🙂