Dunno. But you could try reloading or updating the firmware.
Use the Manual method. There’s no need to install the updater.
http://forums.sandisk.com/t5/Fuze/Sansa-Fuze-Firmware-Update-01-02-31-amp-02-03-33/td-p/139175
Or, basically, see what hardware version your unit is. (Settings/System Settings/Info/ version–begins with 1 or 2.) Go to the All Regions link for 1 or 2 and download the .zip file. Unzip it and drag FuzeA.bin onto your Sansa Fuze driveletter.