Custom oEmbed site no longer working

We have an internal installation of WordPress multisite and we also have a homegrown video sharing application. The video app provides code that can be placed in a blog post that will display the video in a player. The provided short code is something like [embed width='640' height='360'] (our custom stuff here) [/embed].

In order to make this work, I added the following code to a MS plugin:

add_action('plugins_loaded','add_oembed_ivideo');
function add_oembed_ivideo()
{
    global $my_oembed_url;

    $string = $my_oembed_url . '*';
    $provider = $my_oembed_url .  'videoUtils.asmx/oEmbedBlogs';
    wp_oembed_add_provider($string, $provider);
}

It has worked for quite a while, but now it simply displays a hyperlink of the short code provided from our video application. Unfortunately, it’s on an installation that isn’t used much, and I can’t determine when the problem started.

Would anyone know where to start troubleshooting?