in the WA_eCart/PP_ECO_Scripts/PP_ECO_PHP.php try changing:
if ($useSB) {
$soapObj->soapURL = "https://api-3t.sandbox.paypal.com/2.0/";
}
to:
if ($useSB) {
$soapObj->soapURL = "https://api-3t.paypal.com/2.0/";
}
it may not be passing the transaction to the live server. This will force it to use the live server.
the website url is stored in the power store 3 database in the wa_settings table.
you can change the address for the root url to use https instead of http.