Page breaks and bookpart

[Nick Payne]

If I have a number of scores that I'm collecting together using 
bookpart, with a separate title page at the front, and I use \pageBreak 
between two of the scores to minimise or eliminate page turns within a 
score, the text on the overall title page is being repeated on the blank 
page. With the example below, I just want the text "This page 
intentionally left blank" to appear on the blank page between the first 
and second scores, but I'm also getting the overall title from the first 
page being repeated on that page.

Removing the \markuplines so that the page should be completely blank 
make no difference to the reappearance of the title.

I also notice that if I have a \pageBreak after the initial title page, 
so that the first score doesn't start on the back of the title page, 
that this has no effect - no blank page is inserted.

Is this a bug or something I'm doing that I shouldn't?

Nick

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\version "2.13.49"

date = #(strftime "%d/%m/%Y" (localtime (current-time)))

\paper {
    first-page-number = 0
    print-first-page-number = ##f
}

\header {
    title = \markup {
        \lower #40 \left-align \center-column {
            \fontsize #6 \bold "Collection Title"
            \lower #3 \fontsize #2 \bold \line { "Composer" }
            \lower #10 \normalsize " "
        }
    }
    tagline = \markup {
        \fontsize #-3.5
        {
            Engraved on \date using \with-url #"http://lilypond.org/";
            { LilyPond \simple #(lilypond-version) (http://lilypond.org/) }
        }
    }
}

\markuplines \table-of-contents

\markup \null
\pageBreak

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\bookpart {
    \header {
        title = ##f
        subtitle = \markup \huge \bold { 1. Piece 1 }
        composer = \markup { Composer }
        parttagline = \markup \fontsize #-3.5
        {
            Engraved on \date using \with-url #"http://lilypond.org/";
            { LilyPond \simple #(lilypond-version) (http://lilypond.org/) }
        }
    }

    \tocItem \markup { Piece 1 }

    \relative c' { \repeat unfold 400 { c4 } }

}

\markuplines { \justified-lines { This page intentionally left blank } }
\pageBreak

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\bookpart {
    \header {
        title = ##f
        subtitle = \markup \huge \bold { 2. Piece 2 }
        composer = \markup { Composer }
        parttagline = \markup \fontsize #-3.5
        {
            Engraved on \date using \with-url #"http://lilypond.org/";
            { LilyPond \simple #(lilypond-version) (http://lilypond.org/) }
        }
    }

    \tocItem \markup { Piece 2 }

    \relative c' { \repeat unfold 400 { c4 } }

}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%