Version 1.0 has serious DRM problems and won't even run on my system without being patched. V1.02 needs a trainer.
I found this on a Russian site. Maybe it will do ya until a proper trainer materializes.
Stubbs the Zombie in Rebel Without a Pulse cheat codes:
Create a text file in the directory with stubbs.exe called init.txt
and enter the following information into the text file:
Save and play!
These 2 cheats enable infinite life (life meter will still go down)
and infinite ammo (ammo will still go down). enjoy.