I have found that when using Mods for STALKER, its always a good idead to make a backup of the ( gamedata folder ), or the folder that you are going to copy over, because if anything goes wrong you can the delete the ( old gamedata ) folder and copy and paste the original back, or the folder that you backed up and copied over, say like,( textures, config, scripts, ETC...).
I,m using the latest patch on my game at the moment 1.4, and the game rocks.