You could try this ...
Move your test for the weight down lower and have it only test when the country is 223 for the US, example, add the additional test in RED and move it down to around:
Code:
if (!IS_ADMIN_FLAG) {
global $cart;
if ($_SESSION['cart']->weight > 4.99 && $order->delivery['country']['id'] == 223) {
$this->enabled = false;
}
}
$this->types = array(
'EXPRESS' => 'Express Mail', // ID="0"
'FIRST CLASS' => 'First-Class Mail', // ID="1"
'PRIORITY' => 'Priority Mail', // ID="2"
'PARCEL' => 'Parcel Post', // ID="3"
'MEDIA' => 'Media Mail', // ID="4"
'LIBRARY' => 'Library' // ID="5"
);
I did not test this, so be sure to test it well for both shipping_estimator and checkout_shipping ...