Fwd: Query regarding virtuoso

I downloaded dbpedia n-quads data from (
http://km.aifb.kit.edu/projects/btc-2012/dbpedia/). I am trying to load BTC
data to Virtuoso using:


 DB.DBA.TTLP_MT(file_to_string_output('/var/lib/virtuoso-opensource-6.1/db/data-0.nq'),'','graph
iri',512);

I am getting the following error:

    *** Error RDFXX: [Virtuoso Driver][Virtuoso Server]Bad datatype code:
DB.DBA.RDF_OBJ_ADD (256, POINT(7.2858 49.0797), 257)
    at line 20 of Top-Level:

DB.DBA.TTLP_MT(file_to_string_output('/var/lib/virtuoso-opensource-6.1/db/data-0.nq'),'','graph
iri',512)


I am unable to understand as to what is going wrong. Can someone please
help.