Originally Posted by taming
I can change all of mine without any problem. I believe if you set it to 0 it will allow adjustments on those books that you cannot adjust line height. I might be wrong about that as I am reaching back to something I did before line height was adjustable on the Kobo device I was using at that time.
Interesting, I think I tried changing everything to 0, but still couldn't adjust it on my Kobo..