I have installed a local Nominatim install on Ubuntu using the instructions located at http://wiki.openstreetmap.org/wiki/Nominatim/Installation and I am using Apache. The installation appears to function as I can open up the web site, see the map, and query the database and get results.
What I am tying to do is access a local version of the API: For example: http://myinstll/search?q=135+pilkington+avenue,+birmingham&format=xml&polygon=1&addressdetails=1
Is there an additional package that needs to be installed or additional steps to expose the API?