Connection to host: passed... Checking database: failed - table prefix already in use!Why is it so?

What errors are you speaking of? The only thing I see posted here is the notice indicating that the installation is already completed (i.e. the table prefix is already in use in the database, because you dumped it in there). When moving servers, you do not need to run the New Installation procedure. You can run an upgrade if you want to (or are changing versions of MODx at the same time), but it is not necessary. Just make sure your original /manager/includes/config.inc.php exists in your new /manager folder, and that it has the new db connection properties for connecting to the db on your new server.
Thanks Jason.
I dumped the sql first and then id a fresh installation of MODx. Maybe after the error messages appeared I went back and started all over again instead of retrying?!
Thanks again.
Thank you very much, Jason..that took care of it.