There are still many "a" and "b" pages with same translation but slightly different look. Every chapter from 1 to 21 has some.
I think those "out-of-order" pages are supposed to be extras, and go after chapter, but were put before it. Chapter 11 still has it - according to summary, "The secret of chocolate mint" is supposed to come after "Things that signify end of summer", but it's uploaded before.