I figured this out...There is a command that allows you to reformat the FAT partition and I tried this but the import problem repeated and it froze up the DP-02. I missed it but there is another command Menu>Disk>Reformat and this displays Partition 3. Partition 3 is the FAT partition and it...
Try clearing history
Before you created the Master did you clear history?
There is a description of this in manual and I've discovered that this history of editing and saves can get large.
Once the history is cleared create Master again and try it again.
Any help on this is appreciated...I have been successful with USB connection to Mac Desktop and have audio files that have been converted to the appropriate .wav format, the 16 bit 44.1kHz mono WAV format with the .WAV extension. The files I've used are easily dragged to the WAV directory once...