There are a number of songs stored in the preset area of the PSR-2000/1000. You can copy these to the user area, but you cannot copy any of them to the floppy disk. You get that serial copy protection enabled notice. I suspect if you started with one of those and changed it, you would still get that notice. Or perhaps your new song was using a name similar to one of the internal songs. Just why Yamaha choose to "copy protect" these songs is a mystery to me. The demo songs should have been supplied on a floppy in the first place and not taken up any of that precious internal memory in the first place.