I made a MUSICDATA folder on a USB drive, then copied a bunch of ZTN files to it. Tried to load them into the PX-5S, but it only sees one of them. Is this how it's supposed to work, or am I doing something wrong? Also, when I use the editor (on Mac) to transfer the ZTN's, I can drag them into the left hand list, but I can't delete them from that list. I have duplicates I'd like to delete, but there doesn't seem to be any way to delete them.