Just an update:
I downloaded a demo DSF file and imported it into Sonar. It converted the DSD to 192K/32 bit. There seemed to be a bit of clipping, so I stuck a brickwall limiter on the master bus at -0.1dBFS.
Exported it to a FLAC Audio file at the same audio bitrate and sample rate.
Well the sound quality is absolutely brilliant even when converted to PCM. It's a little annoying I still have this quirk and possibly it's related to the performance of my system which was once very capable although it may be showing it's age now. :-(