Hi
So am I correct in assuming that the values for site url and homepage are still set in the options table of the database to be those of the original site and that you are over riding these via the wp-config.php file while you build the site on the new account.
You then intend to point the domain to the new site and stop the redirection via the wp-config.php file?
Can you give us a bit more detail such as:
1)What exactly is the error message?
2)What exactly are the entries you have added to the wp-config file
3)What is the temporary url you are using?
I move WordPress sites a lot and my work flow is something like this:
1) Create a new account on the server using either a new domain or, if allowed, a throw away domain just for the process of setting up the account.
This gives a username for the account.
On my server I can then access the website located on this account by going to, for instance:
https://myservername.com/~mythrowawayusername
If your server doesn’t allow you to use the ~username method to access the site you might need to buy a random domain that you can use for this process since you will need it to access the site.
2) Set up the new site and set the Site URL and Homepage to either of the above solutions so you can access the admin etc.
3) Import the posts and pages via the xml import file
4) Transfer over all the media files from the old site to the new
5) Change the Site URL and Homepage to the same domain as your old site
6) Point the domain to the new account
7) Check all the urls are correct for images etc
8) Possibly run a database find and replace to weed out any persistent url issues
I actually don’t usually use the xml import file because it doesn’t import media files etc.
I have sufficient access to my server accounts that I can simply download the whole site as a zip file and download a copy of the database both of which can easily be used to rebuild the site on another account. Its much more reliable and probably faster too.