The code for the include files is using the virtual function:
<?php
//WA eCart Include
virtual("/WA_eCart/ToyoPOPcart_PHP.php");
?>
in the site definition, there is an option called "Create Links Relative To" if you select the "Site" option, dreamweaver uses the virtual function for includes, using the virtual function is only supported in a small number of php servers though. you should select the Document option so that dreamweaver will the require_once function instead.