Lenovo B / G Series :: G580 BIOS Update Sets Password?

I have recently downloaded a BIOS update for the G580 - version 20150, and ever since that I am locked out of the BIOS setup menu. It asks for a password, however I haven't set up one, and such, I am unable to change any of the settings.
 
Changing the values there would be important, because the settings seem to be reset to a default state, for example, I am unable to start any 64bit virtual machines because hardware virtualization is disabled. I was running Qubes OS too, but I am also unable to boot off legacy (MBR partitioned) devices, which I do occasionally to test some new Linux distro when it comes out.

Apropos Linux: as soon as the system starts booting, the screen goes completely blank, and I have to keep pressing brightness-up to see if the system had started. Brightness controls also seem to behave strange under MS Windows too: on the lowest level instead of dimming (what it did before), the screen goes completely blank. The only good thing in this update is that bluetooth now seems to work more reliable under Linux.
 
Is there a way to remove the password lock from the BIOS and/or revert to the previous version to avoid the screen blanking issue? Would reverting the update also remove the password? If the password can't be removed, is there a safe way to change the settings from a running OS?