Can't boot in safe mode/reset RAM

[matosbr]

I have a 2007 Mbp. Whenever I try to boot in safe mode or reset the PRAM and NVRAM the computer just ignores the keys i press, it just boots normally every time.

I can however boot in safe mode with Onyx. So it seems like a keyboard-computer communication problem during startup.

I have Undercover installed, so I changed the firmware password. Can that have something to do with it?

Any tips?

Thanks.

*EDIT*
Okei, so I found out that I can't use boot commands if I have an Open Firmware password.
I guess the question is: Is there another way to reset PRAM and VRAM besides removing the firmware password?