Thanks for your help Govpatel, you are right I can see the mistake I have made.
I did create a folder in the addon domain called “wordpress” and this was my problem. I removed wordpress and re-installed it in the root of my addon domain. Everything is working find now.
Thanks again for you help
Thanks govpatel
I am a more of a windows guy so know nothing of these unix/web things. So I am not sure I understand everything that you said. Looking in Cpanel I have a folder called public_HTML and within that folder I have a number of sub-directories. I have one directory for my add-on domain, and within that I have a wordpress directory. Also within the public_HTML directory I have another wordpress instalation which holds my main site.
My problem is that I want to be able to access http://www.addondomain.co.uk but can’t. I can access it via http://www.addondomain.co.uk/wordpress