Hi everyone,
Here is my findings to my problem with Sleep Mode
I had the same problem, I was using a Verbatim 4Gb class 6 mircro sd card on the M3i Zero, DSI V1.4E.
I changed to a SanDisk 4Gb class 2 microsd card and formated the card in FAT insted of FAT32.
Now it works perfectly no more...