Thanks for the link.
A virus can change BIOS settings so the computer can boot up - in this case there will be no use of the dual bios as the bios will not notice it.
I think that there should be an option to disable flashing bios, to prevent any unwanted modification. Am I right? I can't find such an option.
I would feel much safer if I could disable it. And only enable while flashing bios.