semantic search-import and export functionality

Hi,
when i click on import or export button, nothing is happening. I am just wondering, am i doing something wrong. and also when i click on download rdf file, it is giving me error saying object not found.

Here i am attaching screen shots of my settings. Can somebody plz help me. I really appreciate ur help. I really need this for my project. Thanks in advance.
// Not sure what to put in Base RDF namespace uri: so I left it as default as semanticsearch.org