Im not sure its related, but I used my EE yesterday and was reading my coursework fine, after the update I went to read a few chapters before bed and some of the files in my folder with my coursework were corrupted, I couldnt delete them, so I copied off the good files and grabed the good versions of the corrupted files off of a memory stick and then reformatted the SD card with a full format, not a quick one on a computer... Im back up but would suggest removing the SD card before update... if this was documented, oops... if not, would be a nice addition to the EE to have the device auto unmount the card before performing any OS upgrade...

Thanks,
Ben