This article is from the Frequently Asked Questions for Linux, the Free/Open Source UNIX-like operating system kernel that runs on many modern computer systems. Maintained by David C. Merrill with numerous contributions by others. (v1.0).
A: Your /var/run/utmp is screwed up. You should have
in your /etc/rc.local or /etc/rc.d/*. See If I Screwed Up the System and Can't Log In, How Can I Fix It?. Note that the utmp may also be found in /var /adm/ or /etc/ on some older systems.