On the Settings screen, what is the full version number shown? Is it 3.0.2 (553210206)? If so then it is a
known problem.
Basically 3.0.2 (553210206) is a version of the firmware that the existing update packages don't expect to exist so it refuses to install 3.0.3. You and all the others are going to have to wait for Amazon to release a newer 3.0.3 or 3.0.4.