ok new kobo aura H2O.
Put the backed up files on new kobo..everything is working just like before...BUT!!!
when i started it up the first time the right part of the screen was washed out like a "gradient" from content to blank page...i was MAD and i even go back to the store ...but obiviously the problem did not represent.
that's the moment i realized maybe those e-ink screen have a "memory" effect and if they stay with screen off for too much time they tend to have the "ghost" effect with the image displayed before shutting down ...can you confirm that?
by the way thanks for your great support everyone!