There is a very nice article on this over at Overclockedcafe. YOu can read it here (http://www.overclockedcafe.com/modules.php?op=modload&name=News&file=article&sid=5512)
TL. 8)
I think most motherboards use *safe* settings while you are in the BIOS IE FSB RAM TIMINGS ETC. Thats why you only find out if your settings have worked when you reboot the system.... problem with the Nvidia boards is they seem to run the bios screen with the settings you choose hence why its the only motherboard in my LIFE that I have seen crash in the BIOS.... an act which I though was impossible.
FWIW, Its FAR more important to me to have a stable system so when I found my superb previously splashed MSI motherboard still worked I took the NF7 back and changed it for a 120GB hard disk :D