Install failure but solved now.
Thought I would post this here by way of a heads up. Probably something I did wrong but ...
I decided to start from scratch on the server and returned to a clean CentOS 5.3 install.
This time, because I had a pro licence I decided to download the install.sh from the licence page.
So, I installed Webmin, checked things were looking ok, then tried to install Virtualmin.
I got the following error :