That is really weird. Has DoP playback ever worked on other DACs, or with another software like Foobar? Have you tried other DSD files, such as the demo tracks from 2L? (http://www.2l.no/hires/) As long as all the DSP Studio settings are unticked on JRiver, Mojo should do DoP without any issues. It's often a problem with JRiver or Windows configuration, but the fact that your Mojo doesn't do DoP regardless of ASIO, WASAPI or KS is strange. I'm out of ideas.