@rafaeltcc: There are two different packages that can contain a bridge install bin, that's what @rogerinnyc meant.
You'll want the hotfix, not the full fledged 'old' JB package.
That said, try restarting your device before trying to install the hotfix.
Also, double-check your exact Kindle model against the
wiki. If it's not listed, I'm going to need the first 6 characters of the S/N and the country it was bought/shipped to.