Well, I have solved the above problem just after posting the thread !
The indication was in "Tue Dec 11 12:02:55 2007] [error] [client 10.96.10.10] client denied by server configuration: /usr/local/apache2/htdocs/"
I did not know that SSL needs separate DocumentRoot setting in httpd-ssl.conf ! When I change it from /usr/local/apache2/htdocs/ to /home/web/homepage, it works perfectly !
Now I have a second related question to ask. I want to serve a few folders (e.g. webmail) ONLY under https, and NOT http. How do I achieve that ?