Thanks for your quick reply, Stunts. You and Hash and Seokun and the other devs are amazing.
What I think happened was that I experienced the disappearing soft keys (perhaps after downloading some software that tried to automatically clear memory and space ) and loaded a more user friendly android launcher, while trying to retain the amazon interface for my wife, which integrated with the recovery partition or root system of the boot.
I believe I resolved this (after 6 successful boots after 0 for 5) using Hashes 8.4.3 update @ http://forum.xda-developers.com/show....php?t=2142241
. I am guessing that file updated the bootloader, which seems to have resolved my initial problem.
However, the "Upgrade Your Kindle " box is still grayed out. So, If I did want to go back to 8.4.6, what would you suggest?