piranha, I believe you misread the original post. It's true that the computer asks for the password upon a reboot, even if the BIOS setting for that is disabled, but the real problem is that the correct password is not accepted at the prompt. You have to power off the machine entirely and then turn it back on before it will accept the correct password. Having to enter the password after every reboot is annoying, but not nearly as annoying as when it asks and won't accept the correct answer.
This happens from both Windows 8 and Xubuntu 12.10, so it's not an operating system problem. It does NOT happen if you reboot from the BIOS screen, however.