SInce you are making changes to your hosting setup such that any web address starting www.rbackyard.net actually goes to www.rbackyard.net/rbackyard, you need to stop Zen Cart from then looking for the rbackyard folder that visitors will already be in.

To do this you change these two lines
define('DIR_WS_CATALOG', '/rbackyard/');
define('DIR_WS_HTTPS_CATALOG', '/rbackyard/');
to
define('DIR_WS_CATALOG', '/');
define('DIR_WS_HTTPS_CATALOG', '/');
in both of your configure.php files.