The mrtg rpm package should not create or update the /etc/cron.d/mrtg file when a package update is performed. In my case, i've removed /etc/cron.d/mrtg from my systems because I prefer to run mrtg with RunAsDaemon: Yes in the mrtg.cfg file and start mrtg via /etc/rc.d/rc.local Other users may perfer to run mrtg more or less frequently than default the 5 minute interval or not at all. In either case, installing an update of the mrtg package requires the administrator to manually change or remove the /etc/cron.d/mrtg file to restore desired system operation. To avoid this problem, the /etc/cron.d/mrtg file should only be created when the package is initially installed. If it isn't possible to differentiate an update from an initial installation, the /etc/cron.d/mrtg file should never be created by the mrtg rpm package.
As RHEL-4.9 is last update for RHEL-4 and it is not suitable for new features and should address only security, performance and critical issues, I'm closing that bugzilla WONTFIX. If this functionality is still missing in RHEL-5, feel free to clone that bugzilla against it.