The transformation between OWL and RDF is still based on the transformation between ObjectLogic and each of the ontology languages, i.e. OWL <-> ObjectLogic <-> RDF. Since the transformations between OWL and ObjectLogic as well as RDF and ObjectLogic have changed for 6.1 compared to 6.0, the transformation between OWL and RDF has also been changed.
One particular case is a domain (range) specification in RDF without a related range (domain) specification for the same property. Such a domain (range) specification is not preserved by the RDF to OWL transformation, i.e. gets lost.