Had 5.1.2 but Mr Kindle wanted to update itself real bad, failed because of the hacks, tried again, draining battery like crazy.
Tried manually removing every hack, one by one, for hours, to no avail.
Finally managed to thoroughly read this post (instead of skimming through it) and it was all working wonderfully after just a few minutes (except downloading the 600mb iso, man that was a bummer).
You guys rock.
Particularly ixtab, who never seems to receive as much thanks as he deserves.