/**
 * Retrieve all grouped shipping rates
 *
 * @return array
 */
public function getGroupedAllShippingRates()
{
    $rates = array();

    /* added code */
    $found = false;
    $collection = $this->getShippingRatesCollection();
    foreach ($collection as $rate) {
        if (!$rate->isDeleted() && $rate->getCarrierInstance()) {
            if ($rate->getCarrier() == "freeshipping" /*&& $rate->getMethod() == "freeshipping"*/) {
                $found = true;
            }
        }

    }

    foreach ($collection as $rate) {
        if (!$rate->isDeleted() && $rate->getCarrierInstance()) {
            if (!isset($rates[$rate->getCarrier()])) {
                $rates[$rate->getCarrier()] = array();
            }

            /* added code */
            $storeId = $this->getQuote()->getStoreId();
            switch ($storeId) {
                case 1: // my store -> default store
                    // any order that is not free shipping -> ignore
                    if ($found && !($rate->getCarrier() == "freeshipping" /*&& $rate->getMethod() == "freeshipping"*/)) {
                        continue 2;
                    }
                    break;
            }

            $rates[$rate->getCarrier()][] = $rate;
            $rates[$rate->getCarrier()][0]->carrier_sort_order = $rate->getCarrierInstance()->getSortOrder();
        }
    }
    uasort($rates, array($this, '_sortRates'));
    return $rates;
}