Originally Posted by Sabardeyn
Wild guess, but you might need to escape the parenthesis and quotation characters.
If I'm correct, calibre is interpreting these as programming instructions for how it should process the equation. Not as output instructions for the plugboard.
Of course I could also be totally wrong.
That's what I suspected at first, but the fact that it works fine if the book is part of a series suggests that its my syntax which is the problem.