I do not recommend you to flash your bios, especially if you've just received it. Maybe you don't know but there are probabilities that you can not even boot it after flashing it, and therefore can not reflash it. You can not then rely on the 1 year guarantee if you've broken it with a bad flashing.
I recommend you to wait some months, maybe the flashing software will be more stable than today or there will be a stable and easy way to recover GP32 that cannot boot because of a bad flashing.