But the problem seems to be that http://www.wikidata.org/wiki/Q1000 actually seems to be an information resource, i.e. under this URI html content is directly being returned (rather than being http 303 redirected).
Also, checking with http://validator.linkeddata.org/vapour I received an error about invalid response (I am not sure whether this is a problem with Vapour or Wikidata ...)
Gregor