the pop/imap services are not enabled by default, but this was the behaviour of pre 6.0 Installs. You must manuelly edit /etc/inetd.conf... It's not really a "bug", but would be nice to do that for compatibility and newbie support...
Enabling pop services is a security risk. Red Hat disables these services by default because end users usually do not need to start these services since an ISP typically provides these services.