Your attachment has been disabled for your site's safety. Please don't post your configure files with the database location, name, user and password. That's asking to be hacked.

Your configure settings are confused. Are you trying to move your cart into a sub directory called "zcart"? If so then remove the portions in red below:

define('HTTP_SERVER', 'http://www.mydomain.com.au/zencart');
define('HTTPS_SERVER', 'https://www.mydomain.com.au/zencart');
I'm also puzzled by the bit in red for this entry, but feel that it can't be good and should go:
define('DIR_WS_CATALOG', '/zcart/'); define('DIR_WS_HTTPS_CATALOG', '/zcart/t/');