I guess I have the same issue with Chromium (29.0.1506.0). Codeblock demos won't work because 'codeblock.js' is served with the wrong MIME type (i.e. 'text/plain') and the browser refuses to execute it. You could host your JS file on GitHub pages (i.e. 'github.io' domain) to fix this issue.
edit: Sorry, I didn't notice you were not the poster. I'll create an issue.