[qualiteam]

You should alter "include/orders.php" script.

Find and replace this code:

PHP Code:

if (!empty($payment_methods) && !empty($active_modules['Google_Checkout']))
    array_unshift($payment_methods, array('payment_method'=>"Google Checkout", 'paymentid' => 0)); 


with this one:

PHP Code:

if (!empty($payment_methods) && !empty($active_modules['Google_Checkout']))
    array_unshift($payment_methods, array('payment_method'=>"Google Checkout", 'paymentid' => '0'));