Sorry, I cannot trouble shoot this for you.
It is clearly not an issue with the plugin, as I have tested it on several other sites. Also you can see on our demo site that pdf creation works fine.
Your template is clearly not the standard Joomla default installed templates, and you have a lot of additional components.
I recommend you first switch to JA Purity or Beez and then try it. If it still doesn't work, look at your components.
A blank page is usually a sign of a php error, so switch errort reporting on and you may get a clue.