far cry help.

I need help with far cry on steam. I'm trying to get the cheats to work but it's not working right.

It tells me.
First off, move the DevMode.lua file to the main FarCry Directory
overwritting other file.
Now Start game by adding the '-devmode' parameter, in game

I get in game and I hit the ~ key and put in -devmode but when I hit one of the hot keys for the cheats they don't work.