If you moved to a different host, your conf_global.php file (located in the root folder of your IPB instance) should be updated to reflect the correct mySQL hostname, mysql username, and mysql password provided by your new hosting provider.
<?php
$INFO = array ( 'sql_host' => 'localhost', 'sql_database' => 'MYSQLDB_NAME', 'sql_user' => 'MYSQLDB_USER', 'sql_pass' => 'MYSQLDB_PASSWORD', 'sql_port' => 3306,
IPS won't be able to tell what info to enter in those fields... that would need to be provided by your host. But that's where the database info is entered. 🙂