When talking to the bootlaoder it is the bootloader that supplies the device signature. For some reason the bootloader on your Arduino Mini-04 is returning 00 00 00. Are you selecting the board "Arduino Mini w/ ATmega328"?
Perhaps you got one with a bad bootloader. You could try re-flashing the bootloader. You will need an ISP or an arduino on which you can run ArduinoISP.