I've moved some drum tracks to my computer for some mild editing in Reaper. Afterwards I moved the tracks back to the SD card. I'm able to play the tracks from the Model 24 but when I press record I get a "song file error cannot record." I've tried turning the unit on and off. Seems like if I have just one of these files in a new project it doesn't allow me to record, but it is able to play them back. Thanks for the help.