This is an old revision of the document!
Here is a couple of Peopoly posts regarding SD card usage issues.
We have noticed that a high percentage of file read issues resulted from user deleting gcode file right before adding new gcode to the same SD card. We are still verifying the cause and for now, we recommend user not to delete files from SD card. If you need more space, just format the card using the SD format application here: https://www.sdcard.org/downloads/formatter_4/
We will follow up on the situation
It is best to save gcode to harddrive and copy directly to the sd card’s Gcode directory. Don’t delete or move any files. If you want to start a big print, reformat using SD formater and print.
We believe we have found the problems for this in firmware and SD card reader, but it will take some time to address. Please use above method until fixed.