Guys, I really need help here. I've just installed a clean SL. It's worked fine, but I'm trying to use Disk Utility and it won't let me erase another partition, verify disk permissions or anything! When I try to, it tells me to type my name and password, I do that, and it gives me ''You must type an administrators name and password to make changes to disk utility''. But I just gave it my name and password! I've tryed logging out, and it let me log back in and accepted me no worries, but it won't let me use disk utility or system preferences!