foreach($memberpackageCollection as $mpcKey => $memberpackage) {
    try {
        $orderId = $memberpackage->getOrderIds();
        $personsOrder = Mage::getModel('sales/order')->load($orderId);

        /* Set different payment method */
        $personsOrder->getPayment()->setMethod('checkmo');
        $personsOrder->getPayment()->setMethodInstance(
            Mage::getModel('payment/method_checkmo')->setInfoInstance(
            $personsOrder->getPayment()->getMethodInstance()->getInfoInstance()));

        Mage::unregister('rule_data');
        $orderModel = Mage::getSingleton('adminhtml/sales_order_create');
        $orderModel->initFromOrder($personsOrder->setReordered(true));
        $orderModel->createOrder();
    }
    catch (Exception $e) {
        Mage::logException($e);
    }
}

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '100006914-1' for key 'UNQ_XYYXSALES_FLAT_ORDER_INCREMENT_ID''

Mage::getSingleton('adminhtml/session_quote')->clear();