Shortcodes not working?

Hi, I’m trying to use shortcodes in my posts but for some reason they don’t seem to be working; WP is disregarding them and treating them like text. Here’s one example:
http://www.hackinghistory.ca/lab-01-understanding-html/

Is there something wrong in my configuration – -do I need to enable these shortcodes somewhere? I’m using [sourcecode] but apparently not correctly.. Thanks,
Matt