Well, NO-SUCCESS at all.
I've performed several factory resets and even with nearly no books, and no database tricks (I forgot to tell that I had used Kobo Utils to kill some tiles like the sync one in my original installation), the freezings are just getting more and more frequent. I suspect there's something really broken in the hardware.
Nevertheless I would like to post some important info about H2O software robustness. I've gotten the freezings EVEN WHILE DOING THE FACTORY RESET. (
Because of that I say I did several factory resets).
My H2O has sometimes looked completely bricked: no response to power button, power led completely on, power led on but on a lower brightness intensity than the normal one, power button led blinking madly, screen blocked in the middle of the five square booting screen, whatever you can think of... But even in these crazy situations, combinations of long press (more than 10 s) in either power button or reset pin-hole button have restored the device... You just have to be patient, and perform the long press through both systems till the device recovers (despite the in-the-middle freezings...)
I do make a lot of critics to Kobo, but in this case, I have to tell that
the core recovery system of H2O is just incredible. I don't know how, when or where an image of the original system is stored, but it just works. Has anyone actually bricked one H2O? Because I cannot think any way to do it...
OTOH, by sheer luck, I've just received an answer about my previously
broken Aura HD. So I think I'm going to wait with my unreliable H2O till I got my first reader replacement... (Kudos to
www.redcoon.es ).