another install.php problem

I’ve been through the ‘installation’ forum looking for answers, but still no luck.
I get this error:
Warning: main(/home/thisadd/public_html/blog/wp-includes/wp-db.php): failed to open stream: Permission denied in /home/thisadd/public_html/blog/wp-settings.php on line 24
Fatal error: main(): Failed opening required ‘/home/thisadd/public_html/blog/wp-includes/wp-db.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/thisadd/public_html/blog/wp-settings.php on line 24
whenever I point my browser to wp-admin/install.php .
Here’s my wp-config info:
<?php
/** WordPress’s config file **/
/** http://wordpress.org/ **/
// ** MySQL settings ** //
define(‘DB_NAME’,
‘thisadd_blog’); // The name of the database
define(‘DB_USER’, ‘thisadd_blog’); // Your MySQL username
define(‘DB_PASSWORD’, ‘XXXXXX’); // …and password
define(‘DB_HOST’, ‘localhost’); // 99% chance you won’t need
to change this value
// Change the prefix if you want to have multiple blogs in a single database.
$table_prefix = ‘wp_’; //
example: ‘wp_’ or ‘b2’ or ‘mylogin_’
/* Stop editing */
$server = DB_HOST;
$loginsql = DB_USER;
$passsql =
DB_PASSWORD;
$base = DB_NAME;
define(‘ABSPATH’, dirname(__FILE__).’/’);
// Get everything else
require_once(ABSPATH.’wp-settings.php’);
?>