Magento - checkout onpage registration get password - magento-1.9

Question

I have created an extension to creating md5 password and sync the email and md5 password with our 3rd party db to use in other tool. on the Resignation page works perfect but we have problem on the checkout Resignation, it is not getting the password and has no possibility to sync and save that in the db. here is the code:
in app/code/local/SyncUsers/config.xml
in the events global:
<customer_save_before>
<observers>
<md5password>
<class>membership/observer</class>
<method>storeMD5Password</method>
</md5password>
</observers>
</customer_save_before>
in app/code/local/SyncUsers/membership/Observer.php
public $_singletonFlag = false;
public function storeMD5Password($observer)
{
// Prevent the save_handler to call itself and end-up with infinite loops.
if($this->singletonFlag) {
return;
}
$this->singletonFlag = true;
$event = $observer->getEvent();
$customer = $event->getCustomer();
if ($customer instanceof Mage_Customer_Model_Customer) {
if ($new_password = Mage::app()->getRequest()->getPost('password', false) && strlen($new_password) > 0) {
$customer->setData('md5_password', md5($new_password));
$customer->save();
}
}
}
in the onpage checkout it is not passing the password and not convert them to md5!