... Your plugin offers to search for various fields and it also offers to specify the category... this implies you may not need to specify or specify as you wish.
NEITHER search works and always delivers nothing in return although there are 880 books activated in this category.
I did install the v2.0 search plugin and after the results remains 0... It just does not work.
So what is the next step in identifying the problem. I need to get this resolved.