In addition to what Mark said above: Make routine backups of your Song folders, using the machine's USB function (every session). Periodically backup the entire card, and do a full format. Copy the full backup to the card after. 90 days is what I do. This procedure can detect bad sectors before they become dysfunctional. Copy/Paste files to/from the SD card using the machine's USB function, rather than removing the card from the machine and using a card reader. Always properly disconnect the USB connection.