@Doitsu: There's no need for a 3.2.1+ specific uninstall file, no

.
@timfrost: Check
this thread for more details on how to get the logs/pinpoint what's causing the update to fail.
@z0mtec: Like greyTraveler said, it does sound like there's still some kind of jailbreak/update block still in place. You might want to try uninstalling *everything* jailbreak(s?) included, restart your Kindle, and try again.