$loader->registerPrefixes() and accessing the classes in a view

Hi

We are testing phalcon on an existing project and are trying to access some of our old static classes from a view. We have used the registerPrefixes() function in our index.php:

<?php
$loader = new \Phalcon\Loader();
$loader->registerPrefixes(array(
    "Old_"      => APPLICATION_PATH . "/../library/Old/",
));
$loader->register();

And then we are trying to call a static function from an old class in a view as follows:

<?php
    echo Old_Repo::getData();

Should we have access to this class in the view using registerPrefixes() ?

This gives us a whitescreen with nothing in our error log.

Thanks for your advice