You may have to change the file extension via File Manager or Windows Expplorer before putting the disk back into the MDF, if that's what you're doing instead of transfering the file over MIDI. When a file is saved on the MDF it goes down as name.Bxx if a bulk dump and name.Sxx if a sequence, xx being the file number selected on the MDF for the save. I don't know if the MDF accepts .syx or .mid if the file wasn't saved directly to it. Try changing the extension.Could also be that the MDR button was active instead of SEQ?mn