Just to report that I have had a random restart on my Libra 2 with this firmware 4.33.19759.
It's just over a fortnight since I installed it, and this is the first.
Nothing special on it, just your standard patch and nickel clock, only about a dozen books.
Not connected to the net since installing it, just read a couple of books, turning on and off (sleep) by opening and closing the cover.
Was quietly reading to myself just now when it restarted as I was halfway down a page, not turning or doing anything else.
Oh dear me!