An NPE has been reported in SPO.hashCode(). Unfortunately, we do not yet have the full bop plan or the original SPARQL query. The bop fragment which causes the error is below, as is the stack trace for the NPE. Based on the bop fragment, this is clearly a default graph query with the context being stripped from quads and a distinct filter being applied to the resulting (s,p,o) triples. One hypothesis is that the DummyIV represents an unknown Value in the query and that we should simply be filtering out any solutions on the default graph access path in which the subject (or other position) is not bound.