Originally Posted by MisterMax
Sorry I don't get the point...
what's the practical meaning of "some really poor spots to split on"
The only drawback I've seen is that the epub are about between 10% and 20% bigger (this is because the compression algorithm used by epub is less efficient on many small file)
At the end of an internal file there will be page break. And at 25K files there will be many unnecessary breaks.
My recommandation is NOT to change all your books because of a glitch in the firmware of the reader.
If you can't stand it, use another firmware. That's why I did not use 1.9.17 although I could have fixed the top margin by reconverting all my books.