STEAM games patch automatically unless told otherwise (even then they magically refuse to listen to me and update anyway sometimes) But I have found a way around the crashes for achievements if it helps, I have had no other problem with the game other than my graphics card crapping out (driver malfuction due to intensity). When playing nightmare, it is impossible avoid achievement crashes unless you already achieved them, go hard then replay, because achievements are not earned after that except for finishing the game on whatever campaign (assuming you have all the other, excluding the Nightmare one). Use the trainer as you normally would and start a new game on hard, play the game up until it crashes because of an achievement, then reload the game, open trainer, but don't activate it (even if you don't activate options, trainer is detected and game crashes). Load the last checkpoint, and play from there, the super health hack should stil be working due to, what I believe to be, the health variables being saved on a save file as, whatever the trainer sets them to. When starting a new mission, health reverts to normal, so repeat this process and then finish the rest of a level without trainer. Then play again on Nightmare (if you give a damn about playing the game again for the achievement). All trainer options can be used now since all the achievements for passing a point/mission have been gained. Fly through the levels and play last level normally, since Nightmare has no checkpoints and mission is restarted upon death/crashing, health hack will always lose effect, manually saving does not change this. It will be hell (I imagine) to play any of the last levels on nightmare, but do your best. Hoping this helps, also hoping that made sense.
[Edited by hattrick, 12/25/2010 3:01:04 AM]