Hi Paul,
Okay, so it definitely looks as if you need the Virtualmin version of Apache. They have Suexec pointing at /home rather than /var/www.
Joe tells me that the Virtualmin and CentOS Apache packages are identical, with the exception of where suexec_docroot points.
So how would you go about changing your Apache version to use the Virtualmin repository?
There's a few different ways to go about it, but the ultimate goal would be to install the following packages from here:
Repository:
http://YOUR_LICENCE_KEY:YOUR_SERIAL_NUM@software.virtualmin.com/centos/5.2/i386/Packages:
httpd, httpd-manual, httpd-devel, mod_ssl, and mod_fcgid packages
One way to do it would be to manually download them all, then use RPM to install them in place of your current versions.
I'd still make a solid backup of my config files in /etc and such (or heck, the entire system) before making any changes :-)
-Eric