So I've tested the site search results page and it still has the same bug:
To see go to http://broughtons.demostore.nitrosell.com/store/search.asp
Type in "black door knob" (without the quotes) into the search box.
22 black door knobs are returned - fantastic.
The filters however are a nonsense and if you try and use them it gets worse.
@Donogh knowing what I know now, I would say its done a boolean search but the filters are showing results for an OR based search. This was why Neil hid the panel.
We really need that fixing if we are to be able to leverage the filters on the brand page - can you see my problem?