Problem if no namespace is used

[wartaal]

When I put the following standard example in a file and read it in I get an exception, because the tool expects that there are namespace prefixes for all URIs:

    @prefix dc: <http://purl.org/dc/elements/1.1/> . 
    @prefix ex: <http://example.org/stuff/1.0/> . 

    <http://www.w3.org/TR/rdf-syntax-grammar> ex:editor 
        [ ex:fullName "Dave Beckett"; 
          ex:homePage <http://purl.org/net/dajobe/> ]; 
          dc:title "RDF/XML Syntax Specification (Revised)" . 

When I add tow more namespace prefixes everything is fine.