In 12.3 Milestone 1 or 2, I'm prompted for the root password whenever I try to shutdown or restart from within GNOME session. If I don't supply it, then I get logged off instead. If I try to shutdown or restart from GDM, I'm still prompted for the root password.
Sometimes it just says "Authentication required to power off", other times it says "Authentication required when other users are signed on" - even if no other user is logged on, and even if there's only one user account on the system.
Is this happening to anyone else? I didn't spot anything related on Bugzilla.
I also notice that sometimes I do not have rights to "Unlock" any options in System Settings - the switch is grayed out - which means I can't change the time, add users or printers, etc. But other times the switch is not grayed out.