Before reporting problems please read the user documentation and FAQ. If your problem relates to the address of a particular search result please use the 'details' link to check how the address was generated before reporting a problem.
Please use trac.openstreetmap.org to report problems making sure to set the component to 'nominatim'. You can search for existing bug reports here.
Please ensure that you include a full description of the problem, including the search query that you used, the problem with the result and, if the problem relates to missing data, the osm id of the item that is missing. Problems that contain enough detail are likely to get looked at before ones that require significant research!