Invalid shipping method in magento 1.8.1? - magento-1.8

Question

Invalid shipping method in magento 1.8.1?
When my cart value in 950 - 999 INR but below 950 or above 999 working fine?
One page controller code is below.
Kindly help me
onePageController.php
<?php
require_once Mage::getModuleDir('controllers', 'Mage_Checkout').DS.'OnepageController.php';
class Webly_QuickCheckout_OnepageController extends Mage_Checkout_OnepageController
{
public function saveBillingAction()
{
if ($this->_expireAjax()) {
return;
}
if ($this->getRequest()->isPost()) {
// $postData = $this->getRequest()->getPost('billing', array());
// $data = $this->_filterPostData($postData);
$data = $this->getRequest()->getPost('billing', array());
$customerAddressId = $this->getRequest()->getPost('billing_address_id', false);
if (isset($data['email'])) {
$data['email'] = trim($data['email']);
}
$data['use_for_shipping'] = 1;
$result = $this->getOnepage()->saveBilling($data, $customerAddressId);
if (!isset($result['error'])) {
if (!isset($result['error'])) {
if ($this->getOnepage()->getQuote()->isVirtual()) {
$result['goto_section'] = 'payment';
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
} elseif (isset($data['use_for_shipping']) && $data['use_for_shipping'] == 1) {
$quote =$this->getOnepage()->getQuote();
$quote->getBaseGrandTotal();
$result = $this->getOnepage()->saveShipping($data, $customerAddressId);
if ($quote->getBaseGrandTotal() < 1000) {
$method = 'inchoo_shipping_fixed';
} else {
$method = 'inchoo_shipping_free';
}
// $method = 'flatrate_flatrate';
$result = $this->getOnepage()->saveShippingMethod($method);
Mage::getSingleton('checkout/type_onepage')->getQuote()->getShippingAddress()-> setShippingMethod($method)->save();
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
$result['goto_section'] = 'payment';
} else {
$result['goto_section'] = 'shipping';
}
}
}
$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));
}
}
}