osc.js

//Na linha 399 tem isso

    addObservers: function () {
        $$('input[name="shipping_method"]').each(function (el) {
            el.observe('click', function () {
                checkout.update({
                    'payment-method': 1,
                    'review': 1
                })
            })
        })


//Coloque isso

    addObservers: function () {
        $$('input[name="shipping_method"]').each(function (el) {
            el.observe('click', function () {
                checkout.update({
                    'payment-method': 1,
                    'review': 1
                })
            })
        })
        $$('input[name="payment[method]"]').each(function (el) {     /*Deivison*/
            el.observe('click', function () {
                checkout.update({
                    'shipping-method': 1,
                    'review': 1
                })
            })
        })