Just wanted to say a belated thanks for your help, leandean.
I finally figured out that if you use Yast2 to enable (or re-enable) Apache2 for the current run-level, the changes made to /etc/sysconfig/apache2 will then take effect. This makes sense with what you said. Other things are starting to make sense to this

now too.
It seems like the /etc/sysconfig/ directory is specific to SuSE?

- "Oo-tee-dee!"