EcomGoLive

if you want magento to deault delivery to the billing
address which would seem like the correct way!! but for some
reason only known to magento they do the oppsite
locate the file below and swap the true and false around  

Just navigate to: app/code/core/Mage/Checkout/Block/Onepage/Billing.php

public function isUseBillingAddressForShipping()
{
        if (($this->getQuote()->getIsVirtual()) ||
$this->getQuote()->getShippingAddress()->getSameAsBilling())
 {
            return false;
        }
        return true;
}