Hi guys, thanks for the reply and for the file, anyway I found another way to use the cheats on demon crusher(I hate cheats but that zimmerman was a bit frustrating).
I created a new profile on "man of courage" difficulty, copied the savegame into the new profile directory, I then started a new game with this new profile, typed the cheat and then loaded the savegame of the other profile, and it worked.
After Zimmerman, I just copied the savegame of level 6 in the old profile(demon crusher one)and I continued to play(this way it reset all the cheats)
It's the same old trick of painkiller...
(awesome game, I don't have the problems/bugs listed in the forum, the only thing I noticed it's about "Ambient occlusion" which on low setting it really speed up the game loading/play for me, anyway I can't see differences from low to high)
My specs:
Vista 32
Q6600
2gb Ram Corsair xms2
9800 GT
Thanks again