And you're sure your player is a SP?
well, if you can turn it on, try connecting to your computer when the screen is showing the Formatting...Please Wait... message. If you can do it, be sure about the version of your miniplayer and then try to upgrade again.
BTW when trying the DFU.. did you follow the instructions on the FAQ section?
http://www.meizume.com/index.php?page=faq