I've been obsessing about this all night. What I've found out is that the import feature only works for MONO .WAV files. The files I was trying to import were stereo, made by me in Sibelius. I had no clue as to how to convert them to mono and wasn't sure I really wanted to, as they were...
I am trying to import WAV files from my computer (iTunes) into my DP-01 FX/CD. These are my own compositions, written and recorded through Sibelius so there could be no legal issues.
I've done this before, though it was a 2 or 3 years ago. I can import the WAV files into the portastation just...