Darksiders: Wrath of War
I am not sure about the first but in regards to the achievements issue, from what I have seen at Steam's forum for this game it's most likely not the trainer. In fact, it seems to be happening to almost everyone regardless of using a trainer or not. Seems that the flagging/tracking of the achievements is bugged currently...
Though, it seems restarting the Steam client before starting the game has fixed it for the most part. Anyway, it seems to have helped on my end at least.
[Edited by sabbey, 5/14/2011 10:03:01 PM]
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem