OK. To test whether a dedicated SSL will work I've installed a trial verisign certificate.

In includes/configure.php I have

define('HTTP_SERVER', 'http://www.mydomain.co.uk');
define('HTTPS_SERVER', 'https://www.mydomain.co.uk');
define('ENABLE_SSL', 'true');

and in admin/includes/configure.php

define('HTTP_SERVER', 'http://www.mydomain.co.uk');
define('HTTPS_SERVER', 'https://www.mydomain.co.uk');
define('HTTP_CATALOG_SERVER', 'http://www.mydomain.co.uk');
define('HTTPS_CATALOG_SERVER', 'https://www.mydomain.co.uk');

define('ENABLE_SSL', 'true');

define('ENABLE_SSL_CATALOG', 'false');
define('ENABLE_SSL_ADMIN', 'true');

When I select to sign into an account on my site, the response is "The connection was refused when attempting to contact www.mydomain.co.uk."

Is there anything I've done wrong in the above?

Thanks, Steve

ps I've replaced the actual domain with mydomain in the text here simply because I'm being hypersensitive about posting the link when i've still got admin and setup files as writeable in places.