I'm having a similar problem with a Fuze v1, only worse.
Originally, I had Sandisk firmware 1.02.31. Then I used the Rockbox 1.2.8 utility to install Rockbox 3.7 on my Fuze v1.
I've had some problems with Rockbox which are showstoppers. For one, the Fuze keeps turning itself off while connected via USB. That is very annoying, as it interferes with transferring music to/from the Fuze's internal memory. I cannot make playlists on my PC, because the Fuze keeps turning itself off before I can get anything done.
So I wanted to uninstall Rockbox, and go back to the original firmware. I've tried to do so using the Rockbox utility, but the "uninstallation" feature doesn't work. It keeps telling me that I need to run a "normal firmware update" to remove the Rockbox bootloader.
That isn't working. The Sandisk Updater simply sits there saying "Sandisk Updater is checking for updates. Please wait..." forever.
How can I get Rockbox off my Fuze and go back to the Sandisk firmware?