I did that yesterday. It did restart, suprisingly. I don't know if it'll do it again (sorry, just on the old comp at the moment so I can't really go and reboot it again to see).
Oh, and I emailed ASUS yesterday - man were the replies fast! The person said she was unsure if this reboot issue is related to the BIOS, but she did say to flash it just to test to see if it fixes it. And suprisingly, she also found out that the current CPU I'm using, would function much better with the new BIOS.
So maybe sometime I should give it a flash. I really wanna enjoy this new comp when I can, so I may do it a wee later in future.