In the search bar, if someone types a query and their mouse happens to be below the search bar, when they press enter, it performs the search based on the suggested title or concept that was where the mouse was positioned. This unwanted autocompleting has confused me and others, and I've only just deduced the cause (I think). Most search engines don't do this behaviour, so people don't even think to consider the position of their mouse when typing a search into a search box. It has caused frustration for our librarians and patrons.