Cannot load code snippet in FancyBox

[tigerclaw-az]

I'm trying to get a code snippet loaded within a fancybox, but the snippet is not showiing up at all.

First the link to open a fancybox:

<a class="fancybox" href="#fancybox-asset-image" title="How do I retrieve an asset image?">How do I retrieve an asset image?</a>

Then the content that should be loaded:

<div class="fancybox-hidden" style="display:none;">
    <div id="fancybox-asset-image" style="width:600px;height:400px;">
        [snippet id="55"]
    </div>
</div>

I tested that the [snippet id="55"] does load the content I expect if it's outside of a fancybox.