Sansa Fuze Firmware Update 01.02.31 & 02.03.33

Although you removed the Rockbox firmware, the bootloader still resides there, trying to boot into Rockbox upon startup. To get rid of this, you have to boot into the Sansa mode by holding the REW button while powering up. (I believe this is the procedure; it’s been a long time since I used Rockbox).Then you can re-install the Sansa Firmware, which will wipe out the Rockbox bootloader.