cannot log on as root after upgrade

	I performed a cvs sync today and buildworld. After the system
reboot
      I cannot log on as root, the error message that is shown on
console
      is "login: pam_acct_mgmt(): authentication error".
      I can still log on as a normal user.

      What do I need to do to fix this? Did I screw something up during
      mergemaster ?

	-- Qing