Are you running udev?
If so, the recent upgrade to udev merged the rules and permissions data into one config file - the rules file.
If this file didn't get updated with new permissions (mine didn't either) then you'll have to add in permissions for the virtual consoles. And /dev/null also needs alteration, IIRC.
Take a look at my post on the Gentoo forums if you're not sure how to go about it: