I have downloaded and reinstalled the package. The issue seems to be caused by browser compatibility. The drop down works on Firefox but doesn't work on Safari, which is my default browser - Mac user .
This is the same issue I am having. The drop downs appear for the section and category, but the Articles never populates and I can't choose the event details article.
I have the most recent download (I only purchased on the 15th of Oct.) I also re-installed to make sure.
I am also having the same problem - article selection will not populate for "details" button. Can pick Section and Catagory but "Article" is always empty. Tried using IE8, IE8 in "compatibility mode", and Google Chrome. No luck. It appears there is someone else on another thread having the same issue as well...