i have... no idea really. I had some vbios troubles as well which even ddu couldnt solve the last time around. in the end I had to reinstall windows and just hope that it will never ever happen again. which it hasn't so far ^^
I suspect that there is a combination of mbios and vbios for some settings like power-voltage-frequency-curves and the likes and when switching either bios (m- or vbios), the old "broken" curves no longer apply.