SELinux causes all the troubles

Both SQUID on BEETHOVEN and Mediawiki on Admin experience various problems with SE Linux enabled:

Squid: FTP and all allowed ports are banned by SE Linux

Wiki: cannot loaded files in other formats because MIME type cannot be verified and /usr/bin/convert (image resizing utility) cannot be used by the web server when SE Linux is enabled.

An easy way out: simply disable SE Linux. Do the following in a shell:

- setenforce 0 <--- disable SELinux

- sestatus grep -i mode <--- display SELinux status
--- this should show that:
Current mode: permissive
Mode from config file: permissive