Biblioscape User Community

This is in continuation of attempts described here:

http://support.biblioscape.com/node/1154#comment-3725

I am trying to create a search that would find the references that reside in my folder Architecture but do not belong to category Architecture. Have a look at the image. Why do I get these strange results? There are at least 4 such references according to Biblioscape counting as I mentioned before.

Here is the screengrab