try editing line 9 of the Connections\PowerStoreConnection.php file:
$PowerStoreConnection = mysql_pconnect($hostname_PowerStoreConnection, $username_PowerStoreConnection, $password_PowerStoreConnection) or trigger_error(mysql_error(),E_USER_ERROR);
to:
$PowerStoreConnection = mysql_connect($hostname_PowerStoreConnection, $username_PowerStoreConnection, $password_PowerStoreConnection) or trigger_error(mysql_error(),E_USER_ERROR);
you may need to wait a day for the persistent connections to time out and allow a new connection to be made.
Also, double check the host, username, password, and database name in the connection file to make sure they are correct.