[rrr]

Thanks for quick reply.
It works OK on other books - and on my very very old kindle and on even older kindle keyboard. (They use mobi files made by calibre from the epub files.)
All books are sideloaded epubs.
Tried powering off on - no effect.
May go back to calibre and delete from device and reload.

Tried that - no effect.
Will continue reading this book on kindle because the story is very good then go back to using the kono.
If anyone has any suggestions as to why one book is slow please post here.
I will keep looking here. Thanks.