i got the same problem with Suse 10 and here are the messages for it...
test:~ # chkconfig ipop3 on
ipop3: unknown service
test:~ # chkconfig pop3s on
pop3s: unknown service
test:~ # /etc/init.d/xinetd restart
Shutting down xinetd: done
Starting INET services. (xinetd) failed
any ideas if i run this one netstat -tap | grep pop it does not give me anything in return maybe wrong for my type of linux....