BBCode only works in single post, not full thread

[Sovereign123]

I've been trying to get Syntax Highlighting to work on my board so I added BB Code utilizing google's prettify.

As we can see it works here: http://snpr.cm/Mhtsv5.png
[Link looks like: http://myforum.com/forums/showthread.php?557-Coding-Convention-amp-Guidelines&p=3054#post3054 ]

And it doesn't work here: http://snpr.cm/OE9Y3F.png
[Link: http://myforum.com/forums/showthread.php?557-Coding-Convention-amp-Guidelines ]


My BB Code is this:

<link href="http://myforum.com/prettify/src/prettify.css" type="text/css" rel="stylesheet" />
<script type="text/javascript" src="http://myforum.com/prettify/src/prettify.js"></script>

<script type="text/javascript">
        var theonload = window.onload;
        window.onload = function(){
            theonload();
            prettyPrint();
        }
</script>
<pre class="prettyprint">
{param}
</pre>

Any ideas what the issue could be with that?