Problem with a module for ask a question

Hello I have installed the module to invoke the Quick Question form to ask questions in a form and place it in a precise page: http://www.chirurgia-miniinvasiva.com/espertorisponde.html

I'm noticing that the module in the administrative area, is devoid of the options to associate css classes and if published there seem to be several issues but especially when it is completed always returns the same error: "category not selected"

What's going on? how can I fix and make the form of order?
thanks a lot