Originally Posted by tompe
This sound like writing of information is failing or that the disk in re-mounted read only because of errors. So check if the internal disk is corrupted so you know if this is the cause.
Does the .mbp (.mpb?) file store the last known position in the ebook? I *think* it does, because if I erase it, the ebook opens to the first page. But if so, isn't that the same file used to store the font family to use on the ebook? In which case, the SD card isn't corrupted/read-protected because then NONE of that information would be saved.