interesting that firebug is not logging the errors.... not sure why...

for firefox try these:

https://addons.mozilla.org/en-US/fir...web-developer/

i'm showing a number of files not loading. for example:

http://criticalsystemsincshop.com/in..._script_loader
http://criticalsystemsincshop.com/in...query.form.min
http://criticalsystemsincshop.com/in...mj_category.js

good luck!