Viper GC Extreme Cheats help

[winds]

Hey guys,
I've been trying for a few days to get the cheats working in my gamecube Viper GC Extreme modchip with the cobra 1.6 Bios but to no avail. I tried the infinite ammo cheats for Resident Evil 0 and REmake but none of them seem to work. I typed in the cheats correctly and enabled them. Is there something i'm doing wrong? I
Cheers!