I spoke too early... The two bugs (tile of the last book read on the SD card not showing after powering off and on again) and page number in right margin showing even when not asked are still there. I began a new book (I was 8% in it when the update happened) so I don't know if it's book related or not, but base on my previous experience with those bugs, I'd rather think it's not related. I can cope with that for the moment, but if there was a solution to worabout... At least, no more font size change with every knew chapter

(for the moment)