Thanks for your reply. I suspected that this was the case.
The strange thing though, is that among the default advanced search options there's a field, Metadata Filtering, that actually has this layout. In this field there is only one lookup. The default is "Do not include log & capture metadata", and then there is two more, "Include log & capture metadata" and "Only include log & capture metadata". Also, strangely, if I open "Filter Mode", that is the lookup for Metadata Filtering, the alternative "Do not include log & capture metadata" isn't even there.
Anyway, I was hoping for a layout for filtering in Advanced Search as e.g.
http://www.beyondtheline.org/Video/ but I guess I have to rethink.
Christer