[opensuse] openSUSE 10.x request the root password on the shutdown command

Hi All, I use SUSE since version 6.4... Since version 10.0 until the 10.2, in some occasions, when I execute "shutdown - y - g0" the system asks for the root password. In case that I don't inform the root password, the system isn't off. This doesn't happen when I execute "shutdown - y - g0 - r" or "reboot" or "halt". Somebody knows because of this? Tks for any information about this... Regards, Vinny P.S.: Sorry, but my english isn't good...