Just turn selinux off. setenforce "0" works without rebooting server, but /etc/sysconfig/selinux is correct place to finalize setting..
What's with people recommending to turn off SELinux?! That's just bad advice and like recommending people keep their doors unlocked at all times. Really, stop doing that. SELinux is there for a reason.
Usually it causes more problems. If you have unlimited resources to tune it up, then it possibly helps on the way.
My advice to Alison is to remove Webmin and use the tools that come with CentOS 5.5. Also make sure that phpMyAdmin can only be accessed from your local LAN, use strong passwords, turn on a tight firewall and do
.. and disable password authentication on sshd server.
anything else that one should do to keep the bad guys from gaining illegal access to your server.
The NSA has some nice guides how to keep your server secure. The guides are on this page: http://www.nsa.gov/ia/guidance/security_configuration_guides/operating_syste...
http://www.zlinuxtoday.com/z/wp-content/uploads/2010/06/CIS_RHEL_5.0-5.1_Ben...
-- Eero