Have you tried formatting it?  Mine did the same thing but i formatted it and start fresh.  Be careful when formatting this system.  There is a certain file that you need to back up. The file is FW_IMAGE.BIN.  You may also want to backup all your MP3 files.  After formatting your YP-910, re-start your napster and download one song to your YP-910.  When done, find the FW_IMAGE.BIN that you backed up and re-load it into your YP-910. That should do the trick.
                 Xxavier2
                
 December 2005