I get the same error (FOTA_FATAL) when trying to update firmware to LN510ZVC. Report the failure to Sprint (*2) so they make it an issue. When I called, they told me to go to the Sprint Store and have them hard reset the phone(??). They copy your contacts, hard reset the phone, then paste your contacts back. Something like that. I plan to go the store for the updated software, even though, I'm not experiencing the freeze past the logo screen issue it claims to fix.