Can't use cheats

[Zero]

Hi everybody i recently completed the game, after 16 hours and some minutes of screaming of fear. I want to start a new game, but this time using cheats. The problem is when i do Shift + ; nothing happens. Can somebody give me an helping hand with this?

Thank you :D

[epsileth]

in-game cheats:

http://www.gamefaqs.com/pc/185706-system-shock-2/cheats

user.cfg cheat file:

http://www.gamefaqs.com/boards/185706-system-shock-2/44677735