Thanks for registering! The problem is that the file might be getting corrupted as it is copied to the SD card, so it might be a different file each time. How are you copying the files--by USB connection with the SD card inside the phone, or with the SD card inserted directly into the computer? Try doing the latter, since transferring files over USB to the SD seems to be more likely to cause issues. Also, when copying files to the SD card, try doing it in smaller batches of files, rather than one giant chunk--large transfers also seem to be more prone to corruption.
01-28-2015 09:39 PM